Technique for preparing white carbon black by phosphoric acid precipitation and directly coproducing sodium phosphate

Abstract

The invention relates to a technology for preparing white carbon black by the phosphoric acid precipitation method and directly co-producing sodium phosphate, which comprises homoeothermal co-current flow feeding with the same ratio and heat-insulated reaction, the operating method for controlling gel by violent stirring, and a technological method for liquid solid extraction, purification and washing and removal of residual phosphor. The technology takes sodium silicate and industrial phosphoric acid as raw materials, controls the adding method, the mol ratio of sodium elements to phosphor elements, the reaction temperature, constant-temperature reaction and the operating method for controlling gel particles by violent stirring, adds a given filter aid to improve the filter condition, and adds an extractant to wash away residual phosphor in the white carbon black, so that the product which completely accords with the use requirements is obtained and simultaneously the added filter aid does not influence the use value of by-products and the purity of the obtained by-product monosodium orthophosphate is higher.

Description

technical field [0001] The present invention relates to the process of using phosphoric acid and sodium silicate as raw materials to produce low-residual phosphorus white carbon black product by precipitation method, and co-produce sodium phosphate salt with industrial value, especially a kind of phosphoric acid precipitation method to prepare white carbon black and directly Co-production of sodium phosphate salt process. Background technique [0002] First of all, using sulfuric acid or hydrochloric acid and sodium silicate as raw materials, the technology of preparing white carbon black by precipitation method is complete and has a long history. With the development of the times, the advancement of technology, the improvement of environmental protection requirements, the concept of making full use of resources and optimizing technical and economic indicators continues to deepen. Using sulfuric acid or hydrochloric acid as the raw material to produce sodium sulfate or sodiu...

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Problems solved by technology

Chinese Patent Publication No. CN1686792A discloses a "preparation method of phosphoric acid precipitated silica", and there are two outstanding problems in this method. 2 .nH 2 O or SiO 2 The physical package in the adsorption capacity is very strong, when using H 3 PO 4 When used as an acidifying curing agent, it is difficult to wrap and absorb the crystallized filter cake in SiO after filtration. 2 .nH 2 O or SiO 2 Phosphorus or phosphate compounds in the solids are washed and removed to meet the requirements of use, and the consequence is that the residual phosphorus content in the final product is relatively high

If NaCl phosphate is recovered separately from the mother liquor when water is recovered, the technical difficulty will be very large and troublesome, and the production cost will increase significantly; if the two are recovered as a mixed salt with a mixture, the product The quality is greatly reduced, and the application value and economic value are greatly reduced

Therefore, the auxiliary method of adding NaCl electrolyte to the reaction system for gel precipitation, no matter in terms of technical difficulty or economic cost, will lead to more disadvantages than advantages, and the effect of getting twice the result with half the effort

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