SU979272A1 - Process for producing calcium-sodium chloride-chlorate defoliant - Google Patents

Description

The invention relates to the production of chemicals for agriculture, namely, the production of defoliants used for the processing of cotton before mechanized harvesting of cotton.

A known method for producing chloride-calcium chlorate calcium defoliant by chlorination of calcium hydroxide L1J

The disadvantage of this method is the formation, along with chlorate, of calcium of the same amount of calcium chloride, the excess of which must be removed from the reaction mixture.

The closest technical solution to the invention is a method for producing calcium chloride-chlorate sodium defoliant, including chlorination of the calcium compound in the presence of sodium carbonate, evaporation of the resulting solution, and separation of sodium chloride 2. 20

However, in order to sufficiently separate the precipitate from the solution, it is necessary to use expensive filter presses in corrosion-resistant design,

which leads to a considerable complication in the production and increase in the cost of the product. In addition, in this process, a deficient pyro-calcine salt is used.

The aim of the invention is to simplify the process.

The goal is achieved by using sodium hypochlorite in Jta4ecTEje, a USE molar ratio of calcium ion (1.9-7.5) :.

Calcium hydroxide or a mixture of hydroxyl and calcium hypochloride may be used as the calcium compound.

Claims (2)

Due to the fact that the chloride-chlorate calcium-sodium defoliant must contain calcium and sodium chlorides in strictly regulated quantities, the addition of sodium hypochlorite to the reaction mixture should be carried out in optimum; foam ratios. If the specified ratios in the finished product are disturbed, either too much sodium chloride may be, it is a harmful ballast, or the amount of derived calcium chloride will be insufficient, which contributes to the achievement of the necessary concentration of calcium chlorate in one evaporated solution due to thickening of the solution pa and precipitation of salts cooling the finished product. Experimentally established 4Tq best results are obtained when the hypochlorite is in contact with the calcium ion 1.9-2.5, which is confirmed by the examples below. The raw material for obtaining the defoliant can be not only calcium hydroxide, but also calcium hypochlorite, passing the chlorine of the reaction mixture into chlorate and calcium chloride. Of practical interest is the use of calcium hydroxide and hypochlorite mixtures as raw materials, which are unrealizable wastes of chlorine, bleach and calcium hypochlorite production. An example. 1000 g of milk of lime with Ca content (OHL 12mass is mixed with 10OO ml of sodium hypochlorite solution containing, Mac.% NaC6Ol4, NaCS II, NaOH 2. The molar ratio A | aCPO: Ca 2.2. The solution is chlorinated at 80 + 2 ° C before the acidic reaction according to the universal indicator. Cyd pentium after chlorination is evaporated on a sand bath to achieve an inacterate concentration of chlorate. Solid sodium chloride is separated on a vacuum filter and squeezed to obtain 443.7 g of the evaporated solution and 143.0 g of sodium chloride. Composition of one stripped off solution, g / l: Са {СРО ,,), 432 СаСе-г.372 МаСе44 Composition chlorate -calcium defoliant chloride according to specifications, g / l; Ca (Ceo} 428 + 8 more than 380 NaCe 1 not more than 45 Thus, the resulting solution corresponds to the specification presented for the defoliant. Example 2, 1000 g of milk of lime with a Ca (OH) content of 12% by weight is mixed with 880 g of sodium hypochlorite solution (of the same composition as in example 1). The molar ratio is NqCevO: Ca 1, 9. Further on, according to npmviepy 1. 430.0 g of one evaporated solution and 119.5 g of sodium chloride are obtained. yn-he1 shaky pacTcoj-xi, Ca (CeOa) 7. 2420 .370 MoC e45 The resulting solution corresponds to Y, prepulates it to the defoliant. Example: 1000 g of lime milk with the content of Ca (OH), 2 12% by weight The solution is from 1150 g of sodium hypochlorite solution of the same composition as in the reamer 1. M, the polar ratio is NoC20: Ca, 5. Further in Example 1. 76.0 g of the evaporated solution and 157.5 g of sodium chloride are obtained. ;, Composition of ynajTeHHoro solution, g / l: Ca (CeOj,) .j435 CaC 377 NaCe45 The resulting solution corresponds to the specification imposed on the defoliant. Approximately 1000 g of milk of lime with Ca (OI P 12 wt.% Mixed with 785 g of a solution of sodium hypochlorite of that composition x, as in the example of the molar ratio: Ca- 1.7. Then, as in example 1. G1ol, 421.5 g of the evaporated solution and 107.2 g of sodium chloride are used. Composition of one stripped off solution, g / l: Ca (Ce 0,) 405 4. With further evaporation, the solution thickens; when cooled, the slurry forms a difficult filtering mass, which contains chlorates in the precipitate along with SMF. The resulting solution does not correspond to the specifications, P1, which is a defoliant, due to the noHiDKeHHbnvi content of chlorate and the increased content of calcium chloride. Example 5. 10OO g of milk of lime with Ca (OH) content, j 12 May.% Is mixed with 1250 g of sodium hypochlorite solution of the same composition as in Example 1. The molar ratio of MS (CI): Ca 2, 7 . Then, as in Example 1. 506.8 g of the evaporated solution and 168.3 g of chooride are obtained. Composition of one stripped off solution, g / l: Ca (Ceo)., 430 JaCe81 The resulting solution does not correspond to the specification presented for the defoliant of the increased content of sodium chloride. Thus, in the proposed method, compared with the known method, there are no stages of precipitation and separation of fine calcium carbonate, which not only simplifies the process, but also makes it waste-free, since sodium chloride released during evaporation is easily disposed of in chlorine plants for chlorine production. The proposed method also makes it possible to solve the problem of utilization of sodium hypochlorite solutions, which are formed in large quantities in chlorine plants during sanitary washing of abses with chlorine with an alkali. Claim 1. A method of producing sodium chloride defoliant calcium chlorate, including chlorination of calcium compound in the presence of sodium salt, evaporation of the solution obtained and separation of sodium chloride, in order to simplify the process, sodium hypochlorite is used as sodium salt, taken in a molar ratio to calcium ion (1.9-7.5) :. 2. The method according to claim 1, characterized by the fact that calcium hydroxide or a mixture of calcium hydroxide and calcium hypochlorite is used as a calcium compound. Sources of information taken into account in the examination 1. S. Shraibman. Production of potassium chlorate and other chlorides. M., GONTP NKTP, 1938, p. 34, 217. 2. USSR author's certificate number 142837, cl. A01N 11/02, 1961 (prototype).