FERTILIZER COMPOSITION

Abstract

A fertilizer composition comprising an ammonium nitrate material and an effective amount of a stabilizer material to result in a specific impulse reduction of at least 10% when compared the specific impulse of a commercially available ammonium nitrate composition. The stabilizer material may comprise huntite or magnesite. In one embodiment, stabilizer material is about 10 to about 25 wt. % of the total fertilizer composition.

Claims

1. A fertilizer composition comprising an ammonium nitrate material and an effective amount of a stabilizer material to result in a specific impulse reduction of at least 50% when compared the specific impulse of a commercially available ammonium nitrate composition; wherein the stabilizer material comprises at least one of huntite and magnesite; and wherein the stabilizer material is at least 10 wt. % of the total fertilizer composition.

2. The fertilizer composition of claim 1, wherein the stabilizer material comprises huntite.

3. The fertilizer composition of claim 2, wherein the stabilizer material is from 10 wt. % to 25 wt. % of the total fertilizer composition.

4. The fertilizer composition of claim 3, wherein the stabilizer material further comprises hydromagnesite.

5. The fertilizer composition of claim 4, wherein the stabilizer material comprises from 1 wt. % to 40 wt. % hydromagnesite.

6. The fertilizer composition of claim 3, wherein the stabilizer material further comprises calcium carbonate.

7. The fertilizer composition of claim 3, wherein the stabilizer material comprises huntite, hydromagnesite and calcium carbonate.

8. The fertilizer composition of claim 3, wherein the stabilizer material comprises at least 50 wt. % huntite.

9. The fertilizer composition of claim 3, wherein the stabilizer material comprises from 50 wt. % to 90 wt. % huntite.

10. The fertilizer composition of claim 1, wherein the stabilizer material comprises magnesite.

11. A method comprising: combining an ammonium nitrate material with an effective amount of a stabilizer material to result in a fertilizer composition with specific impulse of at least 50% less than the specific impulse of a commercially available ammonium nitrate composition; wherein the stabilizer material comprises at least one of huntite and magnesite; and wherein the stabilizer material is about 10 to about 25 wt. % of the total fertilizer composition.

12. The method of claim 11, wherein the stabilizer material further comprises hydromagnesite.

13. The method of claim 11, wherein the stabilizer material further comprises calcium carbonate.

14. The method of claim 11, wherein the stabilizer material comprises huntite, hydromagnesite and calcium carbonate.

15. The method of claim 11, wherein the stabilizer material comprises at least 50% huntite.

16. The method of claim 11, wherein the stabilizer material comprises magnesite.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0295] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

[0296] FIG. 1 depicts a schematic of an embodiment of a blast test article in accordance with the instant disclosure;

[0297] FIG. 2 depicts a schematic cut-away side view of the blast test article of FIG. 1, depicting the booster and fertilizer composition to be tested;

[0298] FIG. 3 is a chart depicting % blast suppression;

[0299] FIG. 4 is a chart depicting % blast suppression;

[0300] FIG. 5 is a chart depicting % blast suppression; and

[0301] FIG. 6 is a chart depicting % blast suppression;

DESCRIPTION OF EMBODIMENTS

[0302] Throughout this specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

EXAMPLE

Standard Operating Procedure for Blast Tests

[0303] Test articles refer to the container (PVC pipe or bucket), a mild steel plate (called a witness plate), fertilizer composition (stabilizer material and AN mixed with 6 wt. % or 12 wt. % fuel oil of AN), and a booster (includes C4 explosive in a plastic storage cup). A schematic of a test article is depicted in FIG. 1, while the innards of each test article, including the detonator, booster, and fertilizer composition are shown in FIG. 2.

[0304] The chemistry of ANFO detonation is the reaction of ammonium nitrate with a long chain alkane (C.sub.nH.sub.2n+2) (usually diesel oil) to form nitrogen, carbon dioxide and water. For an ideal stoichiometrically balanced reaction, ANFO requires 94.3% AN and 5.7% FO. In practice, a slight excess of fuel oil is added (6% is standard), as underdosing results in reduced blast. Overdosing does not result in increased or decreased blast but merely more post-blast fumes.

[0305] Samples labelled 12 wt. % fuel oil were samples of ANFO with an additional 6 wt. % fuel oil added. The results for these samples were normalised to reflect a composition with 94 wt. % AN.

Sample Preparation:

[0306] To make a fertilizer composition for the test article, ANFO prills were dry blended with the stabilizer material powder for at least 20 minutes.

[0307] Each test article was weighed empty using a scale with an accuracy of +/−0.2 grams. The resulting mixture was added to each container (PVC with glued end cap or bucket) to within 25 mm of top edge. Each filled test article (ammonium nitrate and stabilizer material, mixed with fuel oil) was weighed on a scale having an accuracy of +/−0.1 ounce.

[0308] Each test article was left to stand with a covering (e.g. plastic bag) applied to prevent ambient moisture from entering the test article. Just prior to testing, the booster (C4 in a plastic cup or bucket) was inserted flush with the top of the pipe, with the detonator wire attached to the booster.

[0309] Boosters for each test article were prepared in small plastic storage cups. A predetermined amount of C4 was measured into each cup. A C4 booster was added to a 8″ diameter tube with blast material to be tested. The total weight of the tube was approximately eight kg (including the blast material).

[0310] Each test article included a 0.25 inch thick mild steel plate (called a witness plate), with a PVC Pipe, base/end cap or PVC bucket. The test article was placed onto a 4½″ stack thick piece of foam (12 inches×12 inches) on a level sand pit.

[0311] Filled test articles were placed onto witness plates and positioned and centred on the witness plate. Cable (Cat6 cable) was routed from the shelter to Over Pressure probes.

[0312] The detonator was placed into the booster, the charge was armed, and the booster was detonated. For each test article, the detonator was Exploding Bridge Wire (EBW) Type RP-83.

[0313] Blast suppression was measured via two blast pressure probes (PCB model), positioned at a distance of 7 m from the test article. Coaxial cable ran from each probe (2 channel, 12 bit, IEPE, 100 kHz) to a computer. Steel rods were positioned between the probes and the target (i.e. test article) to deflect any possible shrapnel.

[0314] For each test, two blast pressure probes were used to measure the pressure versus time of each explosion (kPa*ms). The resulting pressure readings were used to compute the specific impulse of the fertilizer composition for each test article. Blast overpressure (i.e. impulse pressure) was collected for each test article.

[0315] This data was integrated by standard means and divided by the amount of ammonium nitrate present to generate a “specific impulse” (i.e. maximum pressure reading for each blast test impulse). These were measured against a reference specific impulse of ANFO.

[0316] Without being bound by a particular mechanism or theory, stabilizer materials with a specific impulse at approximately the same level as the baseline (AN controls) are considered “inert”, in that it is believed that these materials affect the impulse at the same levels as the concentration dictates (i.e. operate by a mechanical “filler” mechanism).

[0317] Without being bound by a particular mechanism or theory, measurements below the baseline results are considered “suppressants”, in that it is believed that these materials affect the impulse by a chemical reaction or mechanism independent, or in combination with, a dilution factor.

[0318] Blast suppression results on a number of additives were collected and analysed. All the materials tested acted as blast suppressants, and performed as well as or better than the industry standards. The additives were magnesite and a number of hydromagnesite/huntite blends the constitution of which is provided below: [0319] Composite A: 66 wt. % huntite, 31 wt. % hydromagnesite, 3 wt. % calcium carbonate; [0320] Composite B: 71 wt. % huntite, 4 wt. % hydromagnesite, 25 wt. % calcium carbonate; [0321] Composite C: 81 wt. % huntite, 2 wt. % hydromagnesite, 17 wt. % calcium carbonate;

[0322] To determine the relationship between the blast suppression and percentage additive added to the ammonium nitrate, the data is fitted using a logistic function model or an “S-curve” function:

[00001]$y=\frac{C}{1+{\mathrm{Ae}}^{-\mathrm{Bx}}}$

[0323] Where C is the maximum value (max suppression) and A and B are factors that affect the slope and mid-point respectively. This is a common treatment for fitting data and is not specific to blast suppression science. The factors are adjusted to get the best fit (measured by the R2 value) using the raw experimental data.

[0324] In order to identify stabilizer materials with blast suppression and/or desensitization characteristics, the various stabilizer materials were tested (at different wt. %), in a 8″ diameter tube with 200 g booster. The specific impulse was calculated for each test article and the reduction in specific impulse relative to ammonium nitrate with no stabilizer was calculated.

[0325] FIG. 3 presents blast test results for Composite A. Tests were conducted using 6 wt. % fuel oil (Test 1) and 12 wt. % fuel oil (Test 2). The results were combined and modelled.

[0326] FIG. 4 presents blast test results for Composite B. Tests were conducted using 6 wt. % fuel oil (Test 1) and 12 wt. % fuel oil (Test 2). The results were combined and modelled.

[0327] FIG. 5 presents blast test results for Composite C. Tests were conducted using 6 wt. % fuel oil (Test 1) and 12 wt. % fuel oil (Test 2). The results were combined and modelled.

[0328] FIG. 6 presents blast test results for magnesite. Tests were conducted using 12 wt. % fuel oil.

[0329] Various ones of the inventive aspects noted herein above may be combined to yield fertilizer compositions and methods of making and using the same to fertilize soil, while preventing, reducing, or eliminating the fertilizer (AN fertilizer) from being used in explosives and/or improvised explosive devices.

[0330] While various embodiments of the instant disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the instant disclosure.