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AN EXPLOSIVE FORMULATION

20240327312 ยท 2024-10-03

    Inventors

    Cpc classification

    International classification

    Abstract

    Disclosed herein is an explosive formulation for use in reactive ground, and methods and compositions for loading blast holes in reactive ground with such explosive formulations. The explosive formulation comprises: a treatment component, comprising an oxidant; and a blasting component, comprising an explosive.

    Claims

    1. An explosive formulation, comprising: a treatment component, comprising an oxidant; and a blasting component, comprising an explosive.

    2. The explosive formulation of claim 1, wherein the oxidant of the treatment component is selected from the group consisting of nitrates, hypochlorites, percarbonates, perchlorates, and peroxides, optionally selected from the group consisting of sodium hypochlorite, sodium percarbonate, and/or hydrogen peroxide.

    3. The explosive formulation of claim 1, wherein the explosive of the blasting component comprises a nitrate, optionally ammonium nitrate.

    4. The explosive formulation of claim 1, where the treatment component and the blasting component are suitable to be applied sequentially to a blast hole.

    5. A method for loading a blast hole in reactive ground with the explosive formulation of claim 1, the method comprising the steps of: a) applying or loading a treatment component comprising an oxidant to the blast hole comprising or containing oxidisable material to thereby form a treated blasthole; and b) loading the treated blast hole with a blasting component comprising an explosive.

    6. The method of claim 5, wherein the oxidant of the treatment component of the explosive formulation comprises ammonium nitrate, calcium nitrate, potassium nitrate, sodium perchlorate, sodium nitrate, sodium hypochlorite, sodium percarbonate, and/or hydrogen peroxide.

    7. The method of claim 5, wherein the treatment component of the explosive formulation comprises about 20 wt. % or less of the oxidant.

    8. The method of claim 5, wherein the treatment component of the explosive formulation further comprises an acid or a buffer.

    9. The method of claim 5, wherein the pH of the treatment component of the explosive formulation is from about 2.5 to about 7, about 2.5 to about 6, about 2.5 to about 4.5, or about 3 to about 4.

    10. The method of claim 5, wherein the oxidisable material comprised or contained in the blast hole in the reactive ground comprises one or more sulphides or disulphides.

    11. (canceled)

    12. The method of claim 5, wherein the explosive of the blasting component of the explosive formulation comprises a reducible material.

    13-14. (canceled)

    15. The method of claim 5, wherein the reactive ground in which the blast hole is located is hot reactive ground.

    16. The method of claim 5, to wherein the treatment component of the explosive formulation comprises a sulphide dissolution enhancer.

    17. (canceled)

    18. The method of claim 5, wherein the treatment component of the explosive formulation comprises a reaction status reporter.

    19. (canceled)

    20. The method of claim 5, wherein the blast hole is charged with a non-explosive fluid, optionally water, until sufficiently cool prior to, or during step a).

    21. The method of claim 5, wherein step b) is performed at a time after step a), preferably of from about 1 hour to about 5 days, until most or all or a sufficient amount of the oxidisable material which is contactable with the treatment component of the explosive formulation has been oxidised.

    22. The method of claim 5, wherein the method further comprises a step of: monitoring the progress of oxidation of the oxidisable material prior to step b).

    23. (canceled)

    24. The explosive formulation of claim 1, wherein the treatment component comprises from about 10 wt. % to about 20 wt. % sodium nitrate, and from about 5 wt. % to about 10 wt. % citric acid.

    25. A system for loading a blast hole in reactive ground with an explosive formulation, the system comprising: means for applying or loading a treatment component comprising an oxidant to the blast hole; and means for loading a blasting component comprising an explosive into the blast hole, wherein the blast hole is loaded sequentially with the treatment component and the blasting component.

    26. A kit for loading a blast hole in reactive ground with an explosive, the kit comprising: a first component, which is a treatment component comprising an oxidant, and a second component, which is a blasting component comprising an explosive, wherein the first and second components are loaded sequentially into the blast hole.

    27-28. (canceled)

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0107] FIG. 1 shows a control experiment with sand and water, and no pyrite: A) day 0, B) day 1, and C) day 11.

    [0108] FIG. 2 shows a reference experiment with water; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0109] FIG. 3 shows an experiment with aqueous 10% (w/v) ammonium nitrate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0110] FIG. 4 shows an experiment with aqueous 1% (w/v) hydrogen peroxide solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4 and D) day 11.

    [0111] FIG. 5 shows an experiment with an aqueous citric acid solution (adjusted to pH 3); and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0112] FIG. 6 shows an experiment with aqueous 2% (w/v) EDTA solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0113] FIG. 7 shows an experiment with an aqueous 10% (w/v) ammonium nitrate solution (adjusted to pH 3 with citric acid); and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0114] FIG. 8 shows an experiment with an aqueous 10% (w/v) sodium nitrate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0115] FIG. 9 shows an experiment with an aqueous 2% (w/v) Borax (sodium tetraborate decahydrate) solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0116] FIG. 10 shows an experiment with an aqueous 10% (w/v) sodium chloride solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0117] FIG. 11 shows an experiment with an aqueous 2% (w/v) sodium percarbonate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, and C) day 11.

    [0118] FIG. 12 shows an experiment with an aqueous 1% (w/v) weathering solution (a 6% (w/w) FeSO.sub.4.Math.6H.sub.2O, 13.89% (w/w) Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O aqueous solution); and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0119] FIG. 13 shows an experiment with an aqueous 1% (w/v) weathering (a 6% (w/w) FeSO.sub.4.Math.6H.sub.2O, 13.89% (w/w) Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O aqueous solution) and 10% (w/v) ammonium nitrate solution, and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0120] FIG. 14 shows an experiment with an aqueous 2% (w/v) citric acid solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0121] FIG. 15 shows an experiment with an aqueous 2% (w/v) citric acid and 2% (w/v) Borax solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0122] FIG. 16 shows an experiment with an aqueous 2% (w/v) Borax and 10% (w/v) ammonium nitrate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0123] FIG. 17 shows an experiment with an aqueous 2% (w/v) citric acid, 2% (w/v) Borax and 10% (w/v) ammonium nitrate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0124] FIG. 18 shows an experiment with an aqueous 2% (w/v) citric acid and 2% (w/v) EDTA solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 6, and E) day 9.

    [0125] FIG. 19 shows an experiment with an aqueous 10% (w/v) ammonium nitrate and 2% (w/v) EDTA solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 6, and E) day 9.

    [0126] FIG. 20 shows an experiment with an aqueous 10% (w/v) ammonium nitrate, 2% (w/v) citric acid, and 2% (w/v) EDTA solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 6, and E) day 9.

    [0127] FIG. 21 shows an experiment with an aqueous 2% (w/v) citric acid and 10% (w/v) sodium nitrate solution; and a pyrite-containing rock sample: A) day 0, B) day 1, C) day 4, D) day 7, and E) day 10.

    [0128] FIG. 22 shows an experiment with an aqueous 0.1% (w/v) hydrogen peroxide solution; and a pyrite-containing rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0129] FIG. 23 shows an experiment with an aqueous 1% (w/v) hydrogen peroxide and citric acid (adjusted to pH 4) solution; and a pyrite-containing rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0130] FIG. 24 shows an experiment with an aqueous 1% (w/v) hydrogen peroxide and 2% (w/v) EDTA solution; and a pyrite-containing rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0131] FIG. 25 shows an experiment with an aqueous 5% (w/v) sodium nitrate, 5% (w/v) sodium nitrite, and citric acid (adjusted to pH 5) solution; and a pyrite-containing rock sample: A) day 3, B) day 7, and C) day 10.

    [0132] FIG. 26 shows an experiment with an aqueous 10% (w/v) ammonium nitrate solution; and a reactive ground rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0133] FIG. 27 shows an experiment with an aqueous 1% (w/v) hydrogen peroxide solution; and a reactive ground rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0134] FIG. 28 shows an experiment with an aqueous 2% (w/v) EDTA solution; and a reactive ground rock sample: A) day 0, B) day 3, C) day 7, and D) day 10.

    [0135] FIG. 29 shows the results of 70? C. isothermal testing of: A) a 90 g reactive ground sample pre-treated with 90 g of sodium nitrate, 45 g of citric acid and 450 mL of water at 70? C. for 48 hours; and B) a control experiment where 90 g of the reactive ground sample was pre-treated with 450 mL of water at 70? C. for 48 hours.

    [0136] FIG. 30(a) shows the results of 160? C. isothermal testing of: A) a control experiment where 90 g of 10% (w/w) pyrite in sand mixture was pre-treated with 450 mL of water at 70? C. for 48 hours; and B) a 90 g 10% (w/w) pyrite in sand mixture sample was pre-treated with 90 g of sodium nitrate, 45 g of citric acid and 450 mL of water at 70? C. for 48 hours. FIG. 30(b) shows an expanded region of the graph of FIG. 30 (a).

    [0137] FIG. 31 shows an example blast hole treatment according to the inventive method.

    DEFINITIONS

    [0138] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting.

    [0139] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention pertains.

    [0140] Unless the context clearly requires otherwise, throughout the description and the claims, the terms comprise, comprising, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to. For example, a formulation, composition, component, mixture, process or method that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such formulation, composition, component, mixture, process or method.

    [0141] The transitional phrase consisting of excludes any element, step, or ingredient not specified. If in the claim, such would close the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase consisting of appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

    [0142] The transitional phrase consisting essentially of is used to define a formulation, component, composition, process or method that includes materials, steps, features, (sub)components, or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, (sub)components, or elements do not materially affect the basic and novel characteristic(s) of the claimed invention. The term consisting essentially of occupies a middle ground between comprising and consisting of.

    [0143] Where applicants have defined an invention or a portion thereof with an open-ended term such as comprising, it should be readily understood that (unless otherwise stated) the description should be interpreted to also describe such an invention using the terms consisting essentially of or consisting of. In other words, with respect to the terms comprising, consisting of, and consisting essentially of, where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments not otherwise explicitly recited, any instance of comprising may be replaced by consisting of or, alternatively, by consisting essentially of.

    [0144] Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term about. The examples are not intended to limit the scope of the invention. In what follows, or where otherwise indicated, % will mean weight %, ratio will mean weight ratio and parts will mean weight parts.

    [0145] The terms predominantly, predominant, and substantially as used herein shall mean comprising more than 50% by weight, unless otherwise indicated.

    [0146] As used herein, with reference to numbers in a range of numerals, the terms about, approximately and substantially are understood to refer to the range of ?10% to +10% of the referenced number, preferably ?5% to +5% of the referenced number, more preferably ?1% to +1% of the referenced number, most preferably ?0.1% to +0.1% of the referenced number. Moreover, with reference to numerical ranges, these terms should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 1 to 8, from 3 to 7, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, from 8 to 10, and so forth.

    [0147] The terms preferred and preferably refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

    [0148] As used herein, the term hot ground means a ground or rock material that has a temperature of 55? C. or more.

    [0149] As used herein, the term reactive ground means a ground or rock that undergoes a spontaneous exothermic reaction after it comes into contact with a nitrate. The reaction of concern typically involves the chemical oxidation of sulphides (usually of iron or copper) by nitrates and the liberation of potentially large amounts of heat. The process can be unpredictable and so violent that it results in mass explosions.

    [0150] In certain embodiments, the term reactive ground means a ground which contains an average metal sulfide concentration of at least about 0.5 wt. %, 1 wt. %, 2 wt. %, or 5 wt. % in the region where a blast hole is drilled, or is to be drilled. In other words, the material excavated when drilling a blast hole in reactive ground contains an average metal sulfide concentration of at least about 0.5 wt. %, 1 wt. %, 2 wt. %, or 5 wt. %. Alternatively, in the case where a blast hole has already been drilled, the ground will be a reactive ground if ground samples taken from the inner surface of said blast hole contain an average metal sulfide concentration of at least about 0.5 wt. %, 1 wt. %, 2 wt. %, or 5 wt. %.

    [0151] As used herein, the term blast hole should be construed broadly to include a hole which has been drilled into a ground which is to be loaded with one or more explosives, as well as a natural hole or fissure in ground which is to be loaded with one or more explosives.

    Abbreviations

    [0152] AN: Ammonium nitrate; EDTA: ethylenediaminetetraacetic acid; ORP: Oxidation-Reduction Potential; SN: sodium nitrate.

    [0153] Preferred features, embodiments and variations of the invention may be discerned from the following Examples which provides sufficient information for those skilled in the art to perform the invention. The following Examples are not to be regarded as limiting the scope of the preceding Summary of the Invention in any way.

    EXAMPLES

    Formation of Pyrite-Containing Rock Sample

    [0154] 15 g of finely ground pyrite and 135 g of finely ground sand were mixed together to create a 10% (w/w) pyrite-containing rock sample for testing against the pre-treatment solutions.

    General Experimental Test Procedure

    [0155] 10 g of the 10% pyrite-containing rock sample (or in the case of the experiments with samples from reactive ground: 10 g of the reactive ground sample) was added to each sample jar and the solution being trialed was added to this until the sample jar was filled to the 100 mL mark. Samples were mixed well by shaking and allowed to settle (with loose lids to allow for potential gas release).

    [0156] pH and Oxidation-Reduction Potential (ORP) measurements were taken initially and after 24 hours at 40? C. along with photos to allow for visual observation and comparison. Samples were left at 40? C. for 3 more days then moved to 70? C. for a week (11 days total) unless otherwise stated.

    Control Experiment: Sand and Water (without Pyrite)

    [0157] 10 g of sand (rather than the pyrite-containing rock sample) was added to the sample jar, and water was added until the sample jar was filled to the 100 mL mark. The results are summarised in Table 1 below, and the associated images over a period of time after mixing the solution with the sand are shown at FIG. 1: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00001 TABLE 1 Control experiment results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 8.35 8.37 7.69 ORP (mV) 242 160 Observation: some of the very fine Fine particles sand took several hours to settle suspended in water

    Reference Experiment (Water and Pyrite-Containing Rock Sample)

    [0158] The general experimental procedure was followed using water as the solution being trialed. The results are summarised in Table 2 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 2: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00002 TABLE 2 Reference experiment results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 7.18 7.40 6.98 ORP (mV) 205 155.4 Observation: fine pyrite material took several hours to settle. No changes over testing

    Experiment 1 (10% AN Solution and Pyrite-Containing Rock Sample)

    [0159] The general experimental procedure was followed using a 10% (w/v) ammonium nitrate aqueous solution as the solution being trialed. The results are summarised in Table 3 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 3: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00003 TABLE 3 Experiment 1 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 6.77 7.02 7.32 ORP (mV) 198 178 Observation: some brown colouration had developed overnight, assumed to be rust. Shaking mixed in rust no longer visible. By day 11 more rust like brown material had formed and the sand settled at the base was coloured brown

    [0160] The experimental results suggested that the ammonium nitrate solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 2 (1% H.SUB.2.O.SUB.2 .Solution and Pyrite-Containing Rock Sample)

    [0161] The general experimental procedure was followed using a 1% (w/v) H.sub.2O.sub.2 aqueous solution as the solution being trialed. The results are summarised in Table 4 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 4: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00004 TABLE 4 Experiment 2 results 1 day 4 days 11 days T = 0 (40? C.) (40? C.) (70? C. week) pH 6.57 3.89 5.9 3.74 ORP (mV) 295 328 NT Observation: bubbled aggressively for several hours, gas bubbles still present on day 1, by day 3 brown colouration of the sample had occurred, assumed to be rust. All of settled material show signs of brown rust, solution has a slight brow tint.

    [0162] The experimental results suggested that the hydrogen peroxide solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 3 (Acidic Citric Acid pH 3 Solution and Pyrite-Containing Rock Sample)

    [0163] The general experimental procedure was followed using an aqueous solution adjusted to pH 3 with citric acid as the solution being trialed. The results are summarised in Table 5 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 5: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00005 TABLE 5 Experiment 3 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 2.98 3.62 4.46 ORP (mV) 314 131 Observation: solution developed a yellow tingle overnight. Unsure if this is iron citrate or a different citrate or a result of the citric acid breaking down. Yellow colour grew in intensity over time.

    Experiment 4 (2% EDTA Solution and Pyrite-Containing Rock Sample)

    [0164] The general experimental procedure was followed using an aqueous 2% (w/v) EDTA solution as the solution being trialed. The results are summarised in Table 6 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 6: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00006 TABLE 6 Experiment 4 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 10.80 10.80 10.32 ORP (mV) 2.5 ?201 Observation: material remained suspended overnight, some white precipitate was seen on top of the sample, unsure if much interaction occurred with the pyrite. Pale brown precipitate appeared by day 11 and the solution had a brown tint.

    Experiment 5 (10% AN Solution Adjusted to pH 3 with Citric Acid; and Pyrite-Containing Rock Sample)

    [0165] The general experimental procedure was followed using an aqueous 10% (w/v) AN solution adjusted to pH 3 with citric acid as the solution being trialed. The results are summarised in Table 7 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 7: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00007 TABLE 7 Experiment 5 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 2.97 3.84 4.92 ORP (mV) 288 272 Observation: solution developed a yellow tingle overnight. Potentially this is the citric acid, not observed rusting as seen in the 10% AN sample. Colour intensified over the testing period.

    Experiment 6 (10% SN Solution and Pyrite-Containing Rock Sample)

    [0166] The general experimental procedure was followed using an aqueous 10% (w/v) SN solution as the solution being trialed. The results are summarised in Table 8 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 8: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00008 TABLE 8 Experiment 6 results 1 day 11 days T = 0 (40? C.) (70? C. week) PH 7.59 7.49 7.01 ORP (mV) 233 179 Observation: no visual reaction or Interaction occurred. By day 11 a small amount of brown rust was observed on top of the settled material.

    [0167] The experimental results suggested that the SN solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 7 (2% Borax Solution and Pyrite-Containing Rock Sample)

    [0168] The general experimental procedure was followed using an aqueous 2% (w/v) Borax solution as the solution being trialed. The results are summarised in Table 9 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 9: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00009 TABLE 9 Experiment 7 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 9.24 9.24 9.08 ORP (mV) 120 5.1 Observation: Observation: no visual reaction or Interaction occurred. A fine layer of white precipitated on top of everything else by day 11

    Experiment 8 (10% NaCl Solution and Pyrite-Containing Rock Sample)

    [0169] The general experimental procedure was followed using an aqueous 10% (w/v) NaCl solution as the solution being trialed. The results are summarised in Table 10 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 10: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00010 TABLE 10 Experiment 8 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 7.16 7.32 7.05 ORP (mV) 211 95.8 Observation: no visual reaction or interaction occurred.

    Experiment 9 (2% Sodium Percarbonate Solution and Pyrite-Containing Rock Sample)

    [0170] The general experimental procedure was followed using an aqueous 2% (w/v) sodium percarbonate solution as the solution being trialed. The results are summarised in Table 11 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 11: (A) day 0; (B) day 1; and (C) day 11.

    TABLE-US-00011 TABLE 11 Experiment 9 results 1 day 11 days T = 0 (40? C.) (70? C. week) pH 10.78 10.90 10.48 ORP (mV) 27.2 18.8 Observation: the reaction was even more aggressive than H.sub.2O.sub.2. Once it settled no visual change to the sample could be observed. Over the last few days of testing the settled material turned brown, even the sand was coloured.

    [0171] The experimental results suggested that the sodium percarbonate solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 10 (1% Weathering Agent Solution and Pyrite-Containing Rock Sample)

    [0172] The general experimental procedure was followed using an aqueous 1% (w/v) weathering agent solution (a 6% (w/w) FeSO.sub.4.Math.6H.sub.2O, 13.89% (w/w) Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O aqueous solution) as the solution being trialed. The results are summarised in Table 12 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 12: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00012 TABLE 12 Experiment 10 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 2.65 2.65 3.25 2.22 2.84 Observation: solution brown in colour but after 1 day the brown appears to have precipitated out. The yellow-brown material continued to build up on the walls of the plastic jar, liquid was almost completely clear.

    Experiment 11 (1% Weathering Agent and 10% AN Solution; and Pyrite-Containing Rock Sample)

    [0173] The general experimental procedure was followed using an aqueous 1% (w/v) weathering agent (a 6% (w/w) FeSO.sub.4.Math.6H.sub.2O, 13.89% (w/w) Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O aqueous solution) and 10% (w/v) AN solution as the solution being trialed. The results are summarised in Table 13 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 13: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00013 TABLE 13 Experiment 11 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 2.57 2.83 3.24 2.31 2.74 Observation: solution brown in colour but after 1 day the brown appears to have precipitated out. The orange-brown material continued to build up on the walls of the plastic jar, liquid was almost completely clear.

    Experiment 12 (2% (w/v) Citric Acid Solution; and Pyrite-Containing Rock Sample)

    [0174] The general experimental procedure was followed using an aqueous 2% (w/v) citric acid solution as the solution being trialed. The results are summarised in Table 14 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 14: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00014 TABLE 14 Experiment 12 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 2.25 2.14 2.41 1.78 2.33 Observation: overnight increased intensity of the yellow colour of the solution. Intensity continued to increase over testing period.

    [0175] The experimental results suggested that the citric acid chelates Fe ions from the pyrite to form the yellow coloured complex.

    Experiment 13 (2% (w/v) Citric Acid and 2% Borax Solution; and Pyrite-Containing Rock Sample)

    [0176] The general experimental procedure was followed using an aqueous 2% (w/v) citric acid and 2% (w/v) borax solution (a pyrite solubilizing agent) as the solution being trialed. The results are summarised in Table 15 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 15: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00015 TABLE 15 Experiment 13 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) PH 3.53 3.69 3.93 3.40 3.93 Observation: Yellow colour of citric acid solutions appeared, seems less intense than Citric acid alone. Colour intensity increased over testing period.

    Experiment 14 (10% AN and 2% Borax Solution; and Pyrite-Containing Rock Sample)

    [0177] The general experimental procedure was followed using an aqueous 10% (w/v) AN and 2% (w/v) borax solution as the solution being trialed. The results are summarised in Table 16 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 16: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00016 TABLE 16 Experiment 14 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 8.31 7.96 8.13 8.02 8.17 Observation: slight haze in solution, no rust as seen with AN alone. No change over testing period.

    [0178] Without being bound by theory, the inventors postulate that the borate may have precipitated the iron from the pyrite as iron borate, thus preventing formation of iron (III) oxide.

    Experiment 15 (2% (w/v) Citric Acid, 10% AN and 2% Borax Solution; and Pyrite-Containing Rock Sample)

    [0179] The general experimental procedure was followed using an aqueous 2% (w/v) citric acid, 10% (w/v) AN and 2% (w/v) borax solution as the solution being trialed. The results are summarised in Table 17 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 17: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00017 TABLE 17 Experiment 15 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 3.26 3.42 3.65 3.12 3.60 Observation: Solution slightly hazy, yellow colour, no rust as seen for AN alone. Yellow colour intensified over testing period.

    [0180] Without being bound by theory, the inventors postulate that the borate and/or citrate may have chelated the iron from the pyrite, thus preventing formation of iron (III) oxide.

    Experiment 16 (2% (w/v) Citric Acid, and 2% EDTA Solution; and Pyrite-Containing Rock Sample)

    [0181] The general experimental procedure was followed using an aqueous 2% (w/v) citric acid and 2% (w/v) EDTA solution as the solution being trialed. The results are summarised in Table 18 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 18: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 9.

    TABLE-US-00018 TABLE 18 Experiment 16 results 1 day 3 days 6 days 9 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 3.38 3.66 3.78 3.14 3.71 Observation: solution yellow colour. Colour intensified over testing period

    Experiment 17 (10% AN and 2% EDTA Solution; and Pyrite-Containing Rock Sample)

    [0182] The general experimental procedure was followed using an aqueous 10% (w/v) AN and 2% (w/v) EDTA solution as the solution being trialed. The results are summarised in Table 19 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 19: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 9.

    TABLE-US-00019 TABLE 19 Experiment 17 results 1 day 3 days 6 days 9 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 8.32 7.92 8.07 7.72 8.19 Observation: rust precipitate, brown haze in bottom of solution. Brown colour was seen to intensify over the testing period

    [0183] The experimental results suggested that the AN and EDTA solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 18 (10% AN, 2% EDTA, and 2% (w/v) Citric Acid Solution; and Pyrite-Containing Rock Sample)

    [0184] The general experimental procedure was followed using an aqueous 10% (w/v) AN, 2% (w/v) EDTA, and 2% (w/v) citric acid solution as the solution being trialed. The results are summarised in Table 20 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 20: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 9.

    TABLE-US-00020 TABLE 20 Experiment 18 results 1 day 3 days 6 days 9 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 3.42 3.47 3.52 2.90 3.50 Observation: yellow colour in solution, intensity of colour increase over testing period

    [0185] Without being bound by theory, the inventors postulate that the EDTA may have chelated the iron from the pyrite, thus preventing formation of iron (III) oxide.

    Experiment 19 (10% SN and 2% (w/v) Citric Acid Solution; and Pyrite-Containing Rock Sample)

    [0186] The general experimental procedure was followed using an aqueous 10% (w/v) SN and 2% (w/v) citric acid solution as the solution being trialed. The results are summarised in Table 21 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 21: (A) day 0; (B) day 1; (C) day 4; (D) day 7; and (E) day 10.

    TABLE-US-00021 TABLE 21 Experiment 19 results 1 day 4 days 7 days 10 days T = 0 (40? C.) (70? C.) (70? C.) (70? C.) pH 1.67 2.00 1.96 0.98 1.67 Observation: yellow colour in solution. Yellow colour intensified greatly over testing period. Settled material turned a pale off white colour during last 3 days.

    [0187] Without being bound by theory, the inventors postulate that the citrate may have chelated the iron from the pyrite, thus preventing formation of iron (III) oxide.

    Experiment 20 (0.1% Hydrogen Peroxide Solution; and Pyrite-Containing Rock Sample)

    [0188] The general experimental procedure was followed using an aqueous 0.1% (w/v) hydrogen peroxide solution as the solution being trialed. The solution was kept at room temperature over three days. The results are summarised in Table 22 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 22: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00022 TABLE 22 Experiment 20 results 3 days 7 days 10 days T = 0 (RT) (40? C.) (70? C.) pH 8.83 6.98 6.90 Observation: Gassing strongly day 1 was left over weekend to settle. Day 7 a small amount of brown was visible on the surface of the settled material.

    [0189] The experimental results suggested that the hydrogen peroxide solution was able to oxidise the pyrite in the rock sample that was accessible to the solution.

    Experiment 21 (1% Hydrogen Peroxide and Citric Acid pH 4 Solution; and Pyrite-Containing Rock Sample)

    [0190] The general experimental procedure was followed using an aqueous 1% (w/v) hydrogen peroxide and citric acid (adjusted to pH 4) solution as the solution being trialed. The solution was kept at room temperature over three days. The results are summarised in Table 23 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 23: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00023 TABLE 23 Experiment 21 results 3 days 7 days 10 days T = 0 (RT) 40? C.) (70? C.) pH 4.01 2.26 2.53 Observation: solution gassed strongly on day 0, left to settle over weekend, yellow colour intensifying over testing period.

    Experiment 22 (1% Hydrogen Peroxide and 2% EDTA Solution; and Pyrite-Containing Rock Sample)

    [0191] The general experimental procedure was followed using an aqueous 1% (w/v) hydrogen peroxide and 2% (w/v) EDTA solution as the solution being trialed. The solution was kept at room temperature over three days. The results are summarised in Table 24 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 24: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00024 TABLE 24 Experiment 22 results 3 day 7 days 10 days T = 0 (RT) (40? C.) (70? C.) pH 10.12 10.30 9.47 9.67 Observation: solution gassed strongly on day 0, left to settle over weekend. Brown colour seen mostly in lower half of liquid. Colour intensified over testing period

    Experiment 23 (5% Sodium Nitrate, 5% Sodium Nitrite and Citric Acid (pH 5) Solution; and Pyrite-Containing Rock Sample)

    [0192] The general experimental procedure was followed using an aqueous 5% (w/v) sodium nitrate, 5% (w/v) sodium nitrite, and citric acid (adjusted to pH 5) solution as the solution being trialed. The solution was kept at room temperature over three days. The results are summarised in Table 25 below, and the associated images over a period of time after mixing the solution with the pyrite-containing rock sample are shown at FIG. 25: (A) day 3; (B) day 7; and (C) day 10. Note: there was no picture taken at day 0 as NOx was coming off the solution and it needed to be stored in the back of a fume hood.

    TABLE-US-00025 TABLE 25 Experiment 23 results 3 days 7 days 10 days T = 0 (RT) (40? C.) (70? C.) PH 5.01 4.78 3.96 4.35 Observation: no picture at T = 0 as NOx was coming off the solution and it needed to be stored in the back of the fume hood. Yellow colour intensified over testing period.

    Experiment 24 (10% AN Solution; and Reactive Ground Rock Sample)

    [0193] The general experimental procedure was followed using an aqueous 10% (w/v) AN solution as the solution being trialed, and a reactive ground rock sample. The solution was kept at room temperature over three days. The results are summarised in Table 26 below, and the associated images over a period of time after mixing the solution with the reactive ground sample are shown at FIG. 26: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00026 TABLE 26 Experiment 24 results 3 day 7 days 10 days T = 0 (RT) (40? C.) (70? C.) pH 5.92 3.35 3.01

    Experiment 25 (1% Hydrogen Peroxide Solution; and Reactive Ground Rock Sample)

    [0194] The general experimental procedure was followed using an aqueous 1% (w/v) hydrogen peroxide solution as the solution being trialed, and a reactive ground rock sample. The solution was kept at room temperature over three days. The results are summarised in Table 27 below, and the associated images over a period of time after mixing the solution with the reactive ground sample are shown at FIG. 27: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00027 TABLE 27 Experiment 25 results 3 day 7 days 10 days T = 0 (RT) (40? C.) (70? C.) pH 4.36 3.35 3.01 Observation: gassed strongly, left over weekend to settle. Slight yellow colour in solution.

    Experiment 26 (2% EDTA Solution; and Reactive Ground Rock Sample)

    [0195] The general experimental procedure was followed using an aqueous 2% (w/v) EDTA solution as the solution being trialed, and a reactive ground rock sample. The solution was kept at room temperature over three days. The results are summarised in Table 28 below, and the associated images over a period of time after mixing the solution with the reactive ground sample are shown at FIG. 28: (A) day 0; (B) day 3; (C) day 7; and (D) day 10.

    TABLE-US-00028 TABLE 28 Experiment 26 results 3 day 7 days 10 days T = 0 (RT) (40? C.) (70? C.) pH 11.41 9.99 10.20 Observation: pink/orange colour visible almost immediately.

    Experiment 27 (70? C. Isothermal Reactive Ground Test on Reactive Ground Ore Sample with Sodium Nitrate/Citric Acid Pre-Treatment)

    [0196] A 90 g ore sample from a copper mine containing pyrite was mixed with 90 g of sodium nitrate, 45 g of citric acid and 450 mL of water. A control experiment was performed where another sample of the same ore was mixed with 450 mL of water. Both samples were held at 70? C. for 48 hours. Thereafter, the solid was collected and dried. Standard AEISG code isothermal reactive ground tests (as described in Appendix 2 of the Australian Explosives Industry and Safety Group Inc (AEISG) Code of Practice Elevated Temperature and Reactive Ground: Version 1.1 Mar. 2007) were performed on the control and test sample, i.e. 18 g of each sample was mixed with 18 g of ammonium nitrate and 4 g of a weathering solution (made by dissolving 3 g of FeSO.sub.4.Math.7H.sub.2O in 22 g distilled water; dissolving 5 g of Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O in 13 g distilled water; and combining 2 g of the FeSO.sub.4 solution with 2 g of the Fe.sub.2(SO.sub.4).sub.3). The mixtures were monitored for 48 hrs while being held at 70? C. The results, shown in FIG. 29, show that the incorporation of the sodium nitrate and citric acid in the oxidation pre-treatment step caused a significant drop in the isotherm from 234? C. to 10? C., as compared to the control sample.

    Experiment 28 (160? C. Isothermal Reactive Ground Test on 10% (w/w) Pyrite in Sand Mixture with Sodium Nitrate/Citric Acid Pre-Treatment)

    [0197] A 90 g 10% (w/w) pyrite in sand mixture was mixed with 90 g of sodium nitrate, 45 g of citric acid and 450 mL of water. A control experiment was performed where 90 g 10% (w/w) pyrite in sand mixture was mixed with 450 mL of water. Both samples were held at 70? C. for 48 hours. Thereafter, the solid was collected and dried. Standard AEISG code isothermal reactive ground tests (as described in Appendix 2 of the Australian Explosives Industry and Safety Group Inc (AEISG) Code of Practice Elevated Temperature and Reactive Ground: Version 1.1 Mar. 2007) were performed on the control and test sample, i.e. 18 g of each sample was mixed with 18 g of ammonium nitrate and 4 g of a weathering solution (made by dissolving 3 g of FeSO.sub.4.Math.7H.sub.2O in 22 g distilled water; dissolving 5 g of Fe.sub.2(SO.sub.4).sub.3.Math.9H.sub.2O in 13 g distilled water; and combining 2 g of the FeSO.sub.4 solution with 2 g of the Fe.sub.2(SO.sub.4).sub.3). The mixtures were monitored for 48 hrs while being held at 160? C. The results, shown in FIGS. 30(a) and 30(b), show that the incorporation of the sodium nitrate and citric acid in the oxidation pre-treatment step caused the elimination of the exotherm at 118? C. in the temperature ramp up, as compared to the control sample.

    Example Blast Hole Treatment

    [0198] As shown in FIG. 31A, blast hole 2910 drilled in reactive ground 2920 is preloaded with the treatment component 2930 comprising an oxidant. The treatment component reacts with any sulfides in reactive ground 2920 at the inner surface of blast hole 2910 to oxidise said sulfides. After a period of time whereby the oxidation of the blast hole inner surface sulfides is complete, the treatment component 2930 is removed as shown in FIG. 31B, by displacing it with the blasting component 2940, comprising an explosive, to thereby prevent or at least reduce the risk of premature detonation of the explosive of the blasting component 2940.

    [0199] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. In particular, features of any one of the various described examples may be provided in any combination in any of the other described examples. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows.