42 results about "Calcium arsenite" patented technology

The invention relates to a method for precipitating pentavalent calcium arsenate from an acidic solution, in which arsenic is at least partially in trivalent form. The acidic solution is neutralised before being routed to an arsenic oxidation stage,and a poorly soluble calcium-arsenic compound is precipitated from the solution, in which all the arsenic is pentavalent.

The invention relates to a comprehensive recovery method for complicated materials containing arsenic and valuable metal slag dust, which comprises the following steps of: treating various arsenic-containing materials into a primary rotary kiln to volatilize the arsenic, and treating the materials into a secondary rotary kiln for purifying the arsenic to produce arsenic products containing 99.5 percent of As2O3; carrying out reduction melting on primary and secondary rotary kiln slag through a blast volatilization furnace, returning produced high-arsenic smoke dust back into the primary rotary kiln for treatment, using furnace slag as cement plant raw materials and zinc raw materials for carrying out resource treatment after the forced reduction arsenic removal and zinc volatilization through a fuming furnace, carrying out alkaline oxidation refining treatment on produced arsenic containing alloy, recovering lead, antimony, bismuth, silver and the like in the arsenic removal alloy according to the conventional method, carrying out crushing alkali dissolution and filtering on refined alkali slag with 5 to 15 percent of As2O3 and about 5 to 15 percent of valuable metal content, returning slag back into the blast volatilization furnace to be treated, introducing CO2 into tin and arsenic containing solution for precipitating the arsenic, using filtered stannic oxide as high-tin raw materials to be sold, carrying out arsenic precipitating and filtering through adding Ca(OH)2 into arsenic containing filter liquor, returning calcium arsenate slag back into the primary rotary kilnfor treatment after the filtration, and evaporating and concentrating the rest alkali liquid for recovering the alkali. The whole technical process of the method provided by the invention is simple and smooth, economic benefits and environment benefits are very obvious.

The invention relates to a method for preparing high-stability solid arsenic minerals through a distributed crystallization method. The method comprises the following steps: removing arsenic from a high-arsenic-content solution and curing the solution, so as to carry out harmless treatment on the arsenic-containing solution. According to the method disclosed by the invention, trivalent arsenic in the arsenic-containing solution is catalytically oxidized into pentavalent arsenic; and the oxidized solution is synthesized into the high-stability solid arsenic minerals through a lime arsenic settling method and the distributed crystallization method, and the high-stability solid arsenic minerals can be directly stockpiled. Calcium arsenate is obtained firstly through the lime arsenic settling method, and then the calcium arsenate is turned into the high-stability solid arsenic minerals through the distributed crystallization method; and toxicity extraction meets the specifications of GB5085.3-2007 (solid waste authentication standard-extraction toxicity authentication). The method is short in technological flow and good in arsenic settling effect; the solution subjected to arsenic settling can be directly discharged, and the synthesized solid arsenic minerals are high in stability and can be stably stockpiled within a wide pH range of 2 to 11 and under a strong reducing property condition.