Basic research on the preparation of metallic arsenic by short flow of arsenic-alkali slag from antimony smelting

Metal arsenic is the core raw material of semiconductor materials. The arsenic content in antimony smelting arsenic-alkali slag is high and the composition is complex. The key to the preparation of metal arsenic is the efficient separation of arsenic and various impurities. In this paper, based on the principle of arsenic geochemical mineralization, innovatively put forward the theory of high-precision mineralization and precipitation of arsenate complex salt, developed the key technology of one-step reduction and roasting for the preparation of metallic arsenic by arsenate complex salt precursor, and broke through the problem of high-efficiency separation of arsenic and alkali in high alkali/salt solution and similar impurities, and realized the high-efficiency preparation of metallic arsenic by short flow of arsenic-containing solid wastes. The study shows that: the use of hydrogen peroxide for oxidative leaching to achieve efficient and selective removal of arsenic in arsenic alkali slag, the optimal reaction conditions in the leaching solution of alkali, arsenic and sulfur components of high content; through carbonization treatment of leaching solution recovery of alkali, the alkali content of the product up to 98.79%; arsenic acid complex salt mineralization precipitation to achieve the selective separation of arsenate and bicarbonate, with arsenic slag grade up to 29.75%; by adding carbon powder for reduction roasting to the arsenic slag, the high arsenic slag in the high arsenic slag, the high efficiency of arsenic and alkali, similar impurities. By adding carbon powder to the high arsenic slag reduction roasting treatment, the purity of 99.81% of the metal arsenic monomers, monomers of arsenic in antimony, sulfur impurities in the content of only 0.03% and 0.16%, analyze the reduction of the roasting process and the condensation process of the relationship between the temperature and the free energy of Gibbs can be seen to avoid the impact of monomers of metal arsenic quality, sulfate reduction process should be set at a temperature of 620 ° C, to increase the reduction of the material carbon powder dosage or Increasing the amount of reducing substance carbon powder or elevating the reduction roasting temperature are both favorable to improve the reduction volatilization efficiency and reduce the content of sulfur impurities in the monolithic arsenic. This study can not only provide a theoretical basis for the resourceful disposal of arsenic-containing solid waste, but also is expected to provide technical support for the efficient preparation of metallic arsenic.