SU701939A1 - Method of preparing lead silicate - Google Patents

Description

(54) METHOD FOR OBTAINING LEAD SILICATE

one

This invention relates to inorganic chemistry and may find use in the production of lead silicate. .

A method of producing silicate silicate is known by precipitating it from a mixture of aqueous solutions of lead nitrate and sodium silicate in a continuous process by heating 1.

There is also known a method for producing lead silicate from lead fiber or metallic lead by treating with nitric acid, filtering the resulting lead nitrate solution, reacting it with lead silicate solution, separating to form a lead silicate precipitate from the mother liquor, washing the bottom and drying 2

 The disadvantage of these methods is the formation of a large amount of harmful lead-containing effluent that carries a significant amount of valuable lead nitrate component to the mother liquor, which reduces the yield of lead silicate.

The aim of the invention is to increase the yield of lead silicate and reduce harmful effluent during its production.

The goal is achieved by producing lead silicate by treating gluta with nitric acid, filtering the resulting lead nitrate solution, then reacting it with sodium silicate solution, separating the precipitate of the syrup from the mother liquor, washing the latter and drying it, followed by treating the separated mother liquor caustic solution soda until the pH of the environment is 9.3-10.3 at 6b-94 ° C, by separating the precipitate from the suspension and mixing it with the initial lead ght.

The difference of the method is that the mother solution obtained after separation of the precipitate is treated with caustic soda solution to a pH of 9.3-10.3 at the above temperature and a precipitate is formed from the resulting suspension, which is mixed with the initial lead gelat.

Claims (2)

Returning to the original process to the proposed method of lead-containing product processing mother liquor contributes to the penetration-yield of lead silicate as a result of more complete use of the original lead compound and B, at the same time, significantly reduce the amount of hazardous effluents containing lead compounds, P and m e p 1, 1543 kg of water suspension of lead – gloth obtained by mixing 618 kg of lead glue, 75 kg of lead hydroxide to 923.25 kg of water, are treated in a reg.kortora 3540 kg of nitric acid 5086.2 kg p of the lead solution of nitrate is fed to the frame filterpress to separate mechanical impurities, and then poured into a stirred reactor, in which it is mixed with 4389.5 kg of sodium silicate solution with a silicate module of 1.9 and a SiO content of 14%, V 9476 kg of a suspension of lead silicate are obtained by the interaction of the above solutions, which are filtered on an HPA.CM filter press and separated at this 1824.5 kg of lead silicate paste with a moisture content of 45%. The resulting boil is washed from N0 ions with a hot condenser, dried at 80 ° C, and 1021 kg of lead silicate are obtained, 7658 kg of piglet solution separated from filtering silicate of 57 g / l of sodium nitrate and mixed with lead nitrate in an amount ; 0.2 g / l in terms of lead ion, is treated with stirring chi in the reactor with caustic soda solution, p daaEae Ioro in an amount that provides a pH of 9.3 at 6 bc over 35 clays. The coagulated lead precipitate formed in the process of such treatment is separated from the suspension by filtration and served in the amount of 1.75 kg for mixing with lead gum. The purified solution of nitpa.Tv of sodium separated from this precipitate is evaporated to a concentration of 350 g / l and used in production nitrate comp. PRI mme R 2. The process is carried out analogously to Example 1, but when treating the mother liquor with alkali to the pH of medium 10 at 80 ° C for 20 minutes. In this case, 1.75 kg of lead hydroxide precipitate is formed, which then, together with lead lithium, is fed to the treatment with nitric acid, thus increasing the yield of the target lead silicate. The purified sodium nitrate solution is evaporated to a concentration of 500 g / l for use in the production of nitrate salts. The technique and economic efficiency of the proposed method is determined by the reduction of hazardous effluents and the release of sodium nitrate solution in the form of a marketable product suitable for further use in the chemical industry. Claims A method for producing lead silicate, which includes treatment of lead fiber with nitric acid, filtering the resulting solution of SECN nitrate, interacting it with a solution of silicate, sodium, separating the precipitate from the mother liquor, washing the latter and drying it differs in that in order to increase the yield of the target product and reduce harmful effluents, the mother liquor obtained after separating the precipitate is treated with caustic soda solution to a pH of 9.3-10.3 at 66-94 ° C and from the resulting suspension A nzi precipitate is isolated, which is mixed with the original swigshchEbBvs lact. Sources of information taken into account in the examination 1. The author's certificate of the USSR 136726, cl. C 01 Q 21 / OO, 09.05.60. 2. Technological regulations for lead silicate production at the Beueznikovsky Soda Plant, 1972.