Method for extracting mercury from heavy-metal-related acid mud

Abstract

The invention particularly relates to a method for extracting mercury from heavy-metal-related acid mud, belonging to the technical field of resources and environment. The method comprises the following steps that step 1, the heavy-metal-related acid mud and hydrochloric acid are added into water and are heated; then potassium chlorate is added; reaction is performed at certain temperature to obtain a mixed liquid containing mercuric chloride; step 2, alkali is added in for neutralization to control pH, so that a mixed solution containing mercuric oxide sediment and Na2SeO3 is obtained; solid-liquid separation is performed, and a selenium-containing solution enters a selenium separation system for recycling selenium; step 3, the mercury oxide sediment obtained through separation in the step 2 is dried and is rectified by adopting a continuous vacuum rectification method; and generated mercury steam is condensed and recycled to obtained refined mercury. According to the method, a wet technique is adopted for processing, so that high-efficient separation of mercury and selenium is realized; then the high-purity mercury product is manufactured through continuous vacuum rectification; and smoke pollution caused by direct roasting of the acid mud is avoided.

Description

technical field [0001] The invention belongs to the technical field of resources and environment, and in particular relates to a method for extracting mercury from heavy acid mud. Background technique [0002] Sulfuric acid is an important basic chemical raw material, widely used in non-ferrous smelting, petrochemical, textile printing and dyeing, inorganic salt industry, rubber industry, paint industry, national defense industry, pesticide and medicine, tanning, coking and other industrial sectors. The raw materials for sulfuric acid production mainly include sulfur, pyrite, flue gas from non-ferrous metal smelting, gypsum, hydrogen sulfide and waste sulfuric acid. The sulfuric acid industry has basically formed a three-legged trend of sulfuric acid production, pyrite acid production and smelting flue gas acid production. The output of pyrite acid production and smelting flue gas acid production has reached 60% of the total sulfuric acid production, and it is rising year by...

AI Technical Summary

Problems solved by technology

This method can recover mercury from acid mud, but mercury and selenium in acid mud are evaporated at the same time, gaseous selenium dioxide can oxidize mercury to mercuric oxide, selenium dioxide is reduced to selenium, and selenium-mercury reaction can generate selenium Therefore, the effective separation of selenium and mercury cannot be achieved, and the purity of the recovered mercury product is low; at the same time, the flue gas generated during the process pollutes the atmospheric environment

[0004] At present, the main disposal methods for heavy acid mud are stockpiling or delivery to small enterprises for recycling. However, stockpiling seriously threatens the surrounding environment, and takeaway to small enterprises for recycling mainly has problems such as illegal transfer of hazardous waste, transportation leakage, and low recovery rate. In the recycling process, there are risks such as waste water, waste gas, and unorganized discharge of waste residues