Method for removing arsenic and antimony in industrial wastewater by using smelting furnace slag

Abstract

The invention relates to a method for removing arsenic and antimony in industrial wastewater by using smelting furnace slag. The method comprises the following steps: adding acid to the industrial wastewater containing more than 10mg / L of As and more than 10mg / L of Sb so as to adjust the acidity, and controlling the pH to 0.5-4; adding the smelting furnace slag and an oxidizing agent, enabling the smelting furnace slag to chemically react with or physically adsorb As<3+> and Sb<3+> in the wastewater under acidity and oxidation atmospheres, controlling the temperature at 40-100 DEG C, and carrying out heat preservation reaction for 1-3 hours; adding a neutralizing agent for neutralization, and controlling the pH to 6-9; filtering a solution so as to obtain filtrate and filter residues, if the As contained in the filtrate is less than 0.3mg / L and Sb contained in the filtrate is less than 0.5mg / L, meeting the residue removal standards, feeding the filtrate to a wastewater treatment system for further purifying other impurities, if the As contained in the filtrate is more than 0.3mg / L and the Sb contained in the filtrate is more than 0.5mg / L, repeating the steps till meeting the residue removal standards, and sending the filtrate residues to a filter residue yard for storage. The method has the advantages that the smelting furnace slag is used for replacing a precipitant so as to remove impurities, the arsenic and the antimony in the wastewater are rapidly and efficiently removed within 1 to 3 hours, the removal rate is close to 100%, the method is high in efficiency and low in cost, and the filter residues have good crystal structures, are easy to clarify and filter and contain arsenate and antimonite formed by iron, calcium, magnesium, aluminium, pentavalent arsenic and pentavalent antimony and have stable chemical property.

Description

technical field [0001] The invention belongs to waste water purification technology, in particular to a method for removing arsenic and antimony in industrial waste water by using smelting slag. Background technique [0002] During the wet and pyrometallurgical smelting process of various metals, waste water of harmful elements arsenic and antimony is easy to be produced, and the content of arsenic and antimony can sometimes reach 1~20g / L or even higher. For example, flue gas containing sulfur dioxide, arsenic oxides, and antimony oxides is produced in pyrometallurgy furnaces. The flue gas is purified and washed by multi-stage dynamic waves to obtain high-purity sulfur dioxide, which is then sent to the acid system for recovery and preparation of sulfuric acid. In the above-mentioned flue gas purification and washing process, acidic wastewater containing arsenic and antimony with high concentration (0.5~15g / L) will inevitably be produced. For another example, in the wet pro...

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Problems solved by technology

This method of treating wastewater containing arsenic and antimony, especially wastewater containing high arsenic and antimony, has major problems such as high cost, long time, large amount of slag, strong toxicity of slag, easy dissolution and secondary pollution, and the quality of the treated water cannot be discharged up to standard. , need to take further deep purification treatment

[0004] The smelting slag produced in the process of pyrometallurgy is divided into quenching water quenching slag, natural cooling slag and thermal insulation cooling slag, the main component: FeO or Fe 2 o 3 , CaO, SiO 2 、Al 2 o 3 , MgO, etc. The slag has a complex structure and stable chemical properties. It is a low-value industrial waste. It can be used in the manufacture of cement, inorganic cementitious materials, slag fibers and other industries, but the level of resource utilization is low.

The selling price of smelting slag is extremely low, and it is difficult to sell. Some enterprises use the method of stockpiling slag yards, which needs to occupy a large amount of storage space and consume a lot of cost every year.

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