SU1088750A1 - Method of dehydration of clay-salt suspension in dressing potassium ores - Google Patents

Abstract

The method of dehydrating clay-salt suspensions obtained during the processing of potassium ore includes the processing of suspensions with polyacrylamide and an organic additive followed by filtration of the suspension, characterized in that, in order to increase the filtration rate and reduce the moisture of the salt-salt layers, the process is carried out. in trisodium phosphate solution with the weight ratio of the components trisodium phosphate and fat gudEiNN 1: 1.75-2.25 and with the ratio polyacrylamide and organic Additive 4: 0.2-0.4, based on the Su-g Hoe substance. (L

Description

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 The invention relates to the technology of processing potash ores and can be used in enterprises processing sylvinite and other ores with a high content of clay impurities by the flotation method. A known method for dewatering clay salt suspensions by coagulating them in radial thickeners with the addition of high molecular weight flocculant polyacrylamide (PAA) l. However, the use of one PAA is economically disadvantageous due to its increased consumption, as well as high humidity of the condensed product (45-50%), which leads to significant loss of potassium chloride with the liquid phase of waste products, and excess salt solutions accumulating in the sludge dumps, are a dangerous source of environmental salinization. The combined effect of the mineral agent flocculation with high molecular weight organic flocculant of the polyacrylamide type 2 is known. A disadvantage of this method of dehydrating clay-salt suspensions, along with low efficiency, is the low selectivity of the depression of sludge before flotation of potassium chloride. The closest to the proposed technical essence is the method of dehydration of clay-salt suspensions s1 in potash plants by introducing flocculant based on polyacrylamide, formaldehyde and urea with a ratio of components, parts by weight: Polyacrylamide 0.9-1.1 Formalde guide 0.8-1.4 Urea 0.8-1.5. The disadvantages of this method are the low filtration rate, the high residual moisture of the suspension, and the high cost of flocculation due to the use of expensive components, as well as the additional costs of its synthesis. In addition, the preparation of flocculation is associated with certain technological difficulties arising from the multistage process. The purpose of the invention is to reduce the residual moisture of clay-salt suspensions and increase the filtration rate. The goal is achieved by dehydrating clay-salt suspensions obtained by processing potash ores, including treating the suspension with polyacrylamide and organic, followed by filtering the suspension, using an organic additive emulsion of fatty tar in a solution of trisodium phosphate in a weight ratio trisodium phosphate components and fatty tar Ill, 75-2.25 and At a ratio of polycrylamide and organic additive 4: 0.2-0.4, calculated on the dry matter. Fat tar is a waste of oil and fat that is formed during the purification of vegetable and animal fats in the form of dark brown fluid mass, which includes polyfunctional compounds,%: gossypol, products of its oxidation, transformation and interaction with fatty acids 36 / s. compounds 12; saponified fats, polymerization acids and hydroxy acids in the form of lactones 52. The cost of one ton of fatty tar is 25 rubles. The fatty tar is insoluble in water, but is easily emulsified in an aqueous solution of trisodium phosphate. Such an emulsion, due to the presence of various surfactants in the composition of fatty tar, is well hydrophobicized to the surface of the clay particles. In addition, the introduction of an emulsion of fatty tar in a solution of trisodium phosphate prevents the formation of transient coagulation structures in the volume of suspensions, reduces the plastic viscosity of the suspensions, which ultimately leads to a significant acceleration of the filtration process and a decrease in the residual moisture of the dehydrated product. In order to make an informed choice of the optimal ratio of the components of the emulsion of fatty tar in trisodium phosphate solution, the influence of the ratio of the components of trisodium phosphate and fatty tar on the filtration rate and residual moisture of clay-salt suspensions was studied. The data obtained is presented in Table 1. As can be seen from the above data, the optimum ratio of the components of trisodium phosphate and fatty tar in an emulsion is 1: 1.75-2.25. The decrease in the effectiveness of the emulsion when the ratio is less than 1: 1.75 is due to the insufficient hydrophobic effect of fatty tar on clay particles, and if the ratio is greater than 1: 2.25, an unstable fast-spreading emulsion is formed, as a result of which a significant part of the fatty tar is salted out and is used ineffectively . Table 2 presents the dependences of the residual moisture and filtration rate of clay-salt suspensions on the ratio of polyacrylamide and the added additive (calculated on the dry matter) proposed and known methods, with the ratio of the components trisodium phosphate and fatty tar in the added additive being within optimal limits and is 1: 1.75-2.25. Analysis of the data obtained shows that the optimal ratio of polyacrylamide and additives (emulsion of fatty tar in a solution of trisodium phosphate) is 4: 0.2-0.4, calculated on the dry matter. The deterioration of the process performance in terms of filtration rate and residual moisture when this ratio is changed is explained by the fact that when the ratio is less than 4: 0.2, the hydrophobicine effect of emulsion of fatty tar on clay particles is insignificant, and the increase in the ratio of polyacrylamide and additive is more than 4: 0.4 leads to the predominance of hydrophilicizing effect over the water-repellent. Example. 120 ml of 20% clay-salt pulp obtained from the processing of potash ores is treated with 0.17 ml of an aqueous emulsion containing 2% trisodium phosphate and 3.5% fat tar in a ratio of 1: 1.75. The pulp is stirred for 15 minutes, after which 25.6 ml of 0.5% polyacrylamide solution is introduced, i.e. the ratio of polyarylamide and the additive (emulsion of fat tar in aqueous solution of trisodium phosphate), calculated on the dry matter, : 0.3, stirred for another 1 min and filtered on a Buchner funnel with a measuring cylinder. The resulting precipitate is analyzed for moisture content. Residual moisture 34.9%, filtration rate, determined by the amount of solution filtered from the suspension in 10 minutes, 69-70 ml. A comparative analysis shows that the effectiveness of the proposed method of dewatering clay-salt suspensions in comparison with the known above, the filtration rate increases by 5-12%, and the residual moisture decreases by 4-7%. The proposed method of dewatering clay-salt suspensions obtained from the processing of potash ores reduces the loss of potassium chloride with the liquid phase of production waste, reduces the accumulation of excess salt solutions, which are sources of environmental pollution, and also dispose of them in the national economy. The economic effect of applying the proposed method only by reducing the loss of potassium chloride with the liquid phase of clay-salt suspensions will amount to 420 thousand rubles. in year. Table 1

35 36 39

40 38 35

35

41,8

77 78 84

58 64 69

45 47 51 41.0 34.9

33.2

86 83

70 69 35.6 42.5

64 63

76 75

44.0

The proposed method

Table

Claims (1)

METHOD FOR DEHYDRATING THE CLAY-SALT SUSPENSIONS RECEIVED BY PROCESSING POTASSIUM ORE, including treating the suspensions with polyacrylamide and an organic additive followed by filtering the suspension, characterized in that, in order to increase the filtration rate and reduce the moisture content of the clay-salt suspension, the emulsion is supplemented with clay, emulsion in a solution of trisodium phosphate with a weight ratio of components of trisodium phosphate and tar oil 1: 1.75-2.25 and with a ratio of polyacrylamide and organic additive and 4: 0.2-0.4 in terms of dry matter. to technolorud and can