Steeping liquor used as a means of controlling the risk of fire and explosion of organic extractive materials

Abstract

The invention relates to the use of a concentrated steeping liquor from the starch industry, referred to as corn steep, as a means for controlling the risks of fire caused by self-heating and the risks of explosion of dust caused by the particles and microparticles contained in the inflammable organic materials from the extractive industry, as well as by explosive gases released during the self-heating process during the storage, transport, and/or handling thereof. The concentrated steeping liquor of the invention is diluted with water and mixed with the material to be treated in respective proportions so as to obtain, for an index P up to 315 m, a percentage of fines at most equal to 6%.

Claims

1. A method consisting of mixing a solution comprising corn steep and water with a mass of coal or coke once extracted from a mine, in order to counter risks of fire caused by self-heating and risks of explosion of dust caused by the particles and microparticles contained in the coal or coke as well as explosive gas released by a self-heating process, during subsequent storage, transport or handling of the coal or coke, wherein the mixture of corn steep, water and mass of coal or coke has a passing index P up to 315 m, with a percentage of smalls at most equal to 6%.

2. A method-of countering risks of fire or explosion of coal or coke, according to claim 1, consisting of preparing said solution by diluting corn steep with water with a ratio of dilution with water between 2 and 8%.

3. A method of countering risks of fire or explosion of coal or coke, according to claim 2, consisting of mixing said solution with a dosage ratio, relative to the material to be treated, of between 3 and 12%.

4. A method of countering risks of fire or explosion of coal or coke according to claim 2, further including subsequently transporting or handling a mixture of the diluted solution and the coal or coke.

5. A method consisting of mixing a solution comprising corn steep and water with a mass of coal or coke once extracted from a mine, in order to counter risks of fire caused by self-heating and risks of explosion of dust caused by the particles and microparticles contained in the coal or coke as well as explosive gas released by a self-heating process, during subsequent storage, transport or handling of the coal or coke, wherein the mixing step is carried out with a dosage ratio, relative to the material to be treated, of between 3 and 12%.

6. A method according to claim 5, wherein the mixture of corn steep, water and mass of coal or coke has a passing index P up to 315 m, with a percentage of smalls at most equal to 6%.

7. A method according to claim 5, further including subsequently transporting or handling a mixture of the diluted solution and the coal or coke.

Description

PRESENTATION OF THE FIGURES

(1) The features and advantages of the invention will appear more clearly upon reading the detailed description that follows of at least one preferred implementation mode thereof given by way of non-limiting example and represented in the accompanying figures.

(2) In these figures:

(3) FIG. 1 is the graphical representation, at different periods of time, of the percentage of passing materials as a function of the opening of the sieve in mm;

(4) FIG. 2 is the graphical representation of the variation (in %), in time (days), of the passing material up to 0.315 mm;

(5) FIG. 3 is the graphical representation, with different dilution ratios (3, 5, and 7%), of the passing material up to 0.315 mm (in corrected values at the ratio of 45.6%) as a function of the percentage of solution over fraction 0/Dmax.

DETAILED DESCRIPTION OF THE INVENTION

(6) The tests comprised: a monitoring of progression of particle size, water content and apparent density of a control stock of treated materials situated on the right-of-way of the bulk terminal of the Port of South of France at Ste, over the period Jul.-Sep. 2008, by CEBTP/SOLEN of Montpellier, then by the inventor from Oct. 2008 to Jul. 2009 regarding the monitoring of temperatures, in order to ensure representative external conditions (the control stock representing a mass of approximately 50 t); an optimization study enabling specification of the progression of the percentage of smalls and the apparent density by varying the percentage of the composition tested in a mixture diluted with water, then by varying the percentage of this mixture, referred to as dosage, relative to the quantity of treated material.

(7) The progression monitoring focused more particularly on: the water content; the density; the particle size.

(8) The table below summarizes the monitoring data related to the water content (W) and the apparent density () with the application of the tested composition diluted to 5% of pure product and dosed at 10% on of the material, whose density was before treatment 0.720 t/m.sup.3.

(9) TABLE-US-00001 PERIOD IN DAYS PARAMETERS 8 15 30 60 90 W in % 5.70 7.10 7.0 5.80 6.10 in t/m.sup.3 0.859 0.857 0.805 0.809 0.810

(10) With regard to this monitoring, it can be noted that: the water content varied little; the density remains substantially unchanged.

(11) The following graphs visualize, as a function of time, the data from the particle size monitoring, whose passing material up to 315 m, before the application of the tested composition, was 15% and that up to 80 m at 7.7% (mixture diluted to 5% and dosed at 10%). It is complemented by the evaluation monitoring of the percentage of passing material up to 315 m.

(12) Particle Size Analysis of the Material

(13) FIG. 1 shows, at different periods of time, the percentage of passing material as a function of opening of the sieve in mm;

(14) FIG. 2 shows the variation (in %), in time (days), of the passing material up to 0.315 mm.

(15) The corresponding data are extracted from the following table:

(16) TABLE-US-00002 9 Jul. 16 Jul. 30 Jul. 29 Aug. 30 Sep. 2008 2008 2008 2008 2008 passing 4.7% 6.6% 6.1 6.1% 6.4% material up to 0.315 mm

(17) With regard to this monitored granulometric, it clearly appears that the fine and very fine particles, below 315 microns, were agglomerated from the application of the tested composition, which acted as wetting agent and binder.

(18) This agglomeration, whose advantage primarily concerns fine and very fine particles, focused: principally: on fine and very fine particles having diameters less than 315 m, whose passing material of the order of 6% remained virtually unchanged over 3 months at minimum; secondarily: on much larger grains, going up to the size of 25 mm.

(19) Subsequently, it can be shown that the application of the test composition enables durable binding, over multiple months, of fine and very fine particles, sources of dust lift off.

(20) The optimization study enables specification of the progression of the percentage of smalls as a function of the ratio of dilution with water of the test composition and of the dosage of this diluted composition in the material to be treated.

(21) This study, which focused on three ratios of dilution with water of the tested composition, with 3%, 5% and 7%, was carried out, at the end of three months, over the fraction 0/5 mm of the treated material (petroleum coke), the results of which have been adjusted to take into account the entirety of the treated material in all particle sizes.

(22) The graph table below shows this optimization where it can be observed that the curves corresponding to the dilution ratio of 3% and 5% tend to join when the dosage ratio increases (blue: 3%, red: 5% and green: 7%).

(23) FIG. 3 is the graphical representation, with different dilution ratios (3, 5, and 7%), of the passing material up to 0.315 mm (corrected values at the ratio of 45.6%) as a function of the percentage of solution over fraction 0/Dmax.

(24) The graph in question is complemented by the following table which summarizes the corrected data rounded of the polynomial form: P=ad+b, where P is the passing material in %, d the dosage in % and b a constant of the optimization study as a function of the dilution ratio, for example: 11.50=0.991+12.491 for d=1, at the dilution ratio of 5%.

(25) TABLE-US-00003 Dosage of DILUTION RATIO OF THE TESTED COMPOSITION the diluted 3% 5% 7% mixture on P: passing P: passing P: passing the material material material material (d) up to 315 in % up to 315 in % up to 315 in % 1 14.20 11.50 9.00 2 12.97 10.51 8.03 3 11.75 9.52 7.06 4 10.53 8.53 6.09 5 9.30 7.54 5.13 6 8.08 6.55 4.16 7 6.85 5.55 3.19 8 5.63 4.65 2.22 9 4.41 3.57 1.26 10 3.18 2.85 0.29 11 1.96 1.59 0.00 per 10.3 12 0.73 0.60 12.6 0.00 0.00 linear form P = 1.224 P = 0.991 P = 0.968 d + 15.422 d + 12.491 d + 9.968

(26) These tests show that: the passing material up to 315 m and the mixture dosages are proportional irrespective of the dilution ratios of the composition; for dilution ratios of 3% and 5%, the results are essentially identical from 7% of mixture in the product where the passing materials up to 315 are of the order of 6% to attain approximately 0% to 12.6% of mixture; the dilution ratio of 7%, enables very substantial improvement of the results, the 7% passing materials of the mixture being on the order 3% to attain 0 to 10.3% of mixture; a dilution ratio of 6% can be extrapolated without difficulty: it is of the polynomial form: P=0.952 d+10.952, with a passing material up to 315 of 0 for a dosage of 11.5%, and a passing material of less than 3% to 7% of mixture.

(27) The application of the tested composition has the advantages: durable agglomerating of the particles and microparticles, which enables increase of the grain size as was demonstrated above; avoiding moisture binding by condensation, the tested composition, diluted between 5 to 7% with water, acting as wetting agent and binder, agglomerating the particles and microparticles, thereafter avoiding this moisture binding.

(28) In order to verify these elements, the internal temperatures of the stocks were noted in a stock of petroleum coke treated with the test composition and a stock of untreated petroleum coke. This verification, the data of which are repeated in table below, speaks for itself, the temperature of the treated stock not having varied (temperatures tracked detected at more than 1 m in the interior of the stocks during the months of Jul. 2008 to Jul. 2009).

(29) TABLE-US-00004 Bulk coke Treated coke Date T in C. T in C. 1 Jul. 2008 165 45 8 Jul. 2008 165 45 15 Jul. 2008 160 44.5 22 Jul. 2008 155 48.3 29 Jul. 2008 125 31.5 5 Aug. 2008 150 34.5 12 Aug. 2008 145 34.5 19 Aug. 2008 150 33 26 Aug. 2008 160 30 2 Sep. 2008 115 28.8 9 Sep. 2008 130 30 16 Sep. 2008 120 35 23 Sep. 2008 150 25 30 Sep. 2008 142 40 8 Oct. 2008 120 22 15 Oct. 2008 122 20 22 Oct. 2008 130 23 29 Oct. 2008 145 22 5 Nov. 2008 140 23 12 Nov. 2008 95 25 23 Dec. 2008 110 20 29 Jan. 2009 117 17 27 Feb. 2009 105 16 25 Mar. 2009 110 15 30 Apr. 2009 117 17 22 May 2009 103 22 23 Jun. 2009 105 24 28 Jul. 2009 100 26

(30) According an implementation variation of the invention, the diluted steeping liquor will be mixed with black soap (oil+alkaline solution) in order to increase the wetting properties of the composition.

(31) The corresponding proportion will not exceed 5%.

(32) Of course, the person skill in the art will be able to carry out the invention as described and shown by applying and adapting known means. He will also be able to also foresee other variations without departing from the scope of the invention which is determined by the terms of the claims.