The invention relates to an arsenic-containing waste slag solidified body and a preparation method thereof, and belongs to the technical field of environmental protection. The preparation method comprises the following steps of: treating arsenic-containing waste slag, mixing the treated arsenic-containing waste slag and a curing agent prepared from industrial waste slag and a mineral activated material, a modifying agent, aggregates, water and the like, and stirring, forming and curing the mixed materials to obtain the solidified body with high strength and low arsenic leaching rate. Comparedwith the prior art, the solidification process is simple, low in cost, safe and reliable, and solves the problem of arsenic pollution of the arsenic-containing waste slag.

Arsenic-containing waste slag solidified body and preparation method thereof

Method for recycling arsenic-containing waste residues

The invention provides a method for preparing arsenic trioxide by using arsenic sulfide waste slags. The method comprises the following steps: lixiviating out arsenic sulfide from the arsenic sulfide waste slags by using a sodium hydroxide solution; mixing the extracted arsenic sulfide with water so as to form a slurry, wherein the water is 2-5 times as heavy as the extracted arsenic sulfide; while stirring at room temperature, mixing the slurry with an excess iron persulfate solution to react for 0.5-2 hours; after reaction, filtering so as to obtain a filtrate containing arsenious acid, arsenic acid, sulfuric acid and ferrous sulfate and a sulfur filter cake; introducing sulfur dioxide gas into the filtrate so that the arsenic acid is reduced to the arsenious acid; then distilling, concentrating and cooling the reaction mixture, separating out the arsenious acid; and filtering again so as to obtain an arsenious acid precipitate; and drying the arsenious acid precipitate so as to obtain the arsenic trioxide product. The method has the advantages of short process flow, high arsenic recovery rate, no secondary pollutant and simple equipment, and ensures greatly reduced cost of arsenic recovery, thus the method is worth of popularizing and applying.

Method for preparing arsenic trioxide by using arsenic sulfide waste residue

The invention provides a method for preparing arsenic trioxide by arsenic-containing waste water, which comprises the steps of: adjusting the PH value of the arsenic-containing waste water to be 5.5-6.5 by sodium hydroxide, and filtering out impurity to obtain filter liquor; reacting the filer liquor with excessive copper sulfate solution in a mixing way, adjusting the PH value of reaction solution to be 8.0 by sodium hydroxide, and filtering the reaction solution to obtain copper arsenite precipitate; washing the copper arsenite precipitate by water, mixing the copper arsenite precipitate with the water with 2-5 times of the weight of the copper arsenite precipitate to be sizing agent, stirring under room temperature, feeding sulfur dioxide gas, and filtering after abundantly reacting to obtain copper sulfite dihydrate-containing precipitate and arsenious acid-containing solution; and distilling the arsenious acid-containing solution by means of pressure reduction to be the arsenious acid saturated solution, cooling, crystallizing and drying to obtain an arsenic trioxide product. The method is short in technological process, high in arsenic recovery rate, free of the generation of secondary pollutant, and the equipment is simple so as to greatly lower the arsenic recovery cost, so that the method is thereby being a method which is worth to be popularized and applied.

Method for preparing arsenic trioxide by arsenic-containing waste water

The invention provides a method for preparing arsenic trioxide from arsenic sulfide waste The arsenic sulfide waste is soaked in a sodium hydroxide solution to extract arsenic sulfide, arsenic sulfide mixes with an excessive amount of arsenic acid, and the mixture reacts at a temperature ranging from 40 DEG C to 95 DEG C for 05 to 3 hours, to produce a mixture containing arsenous acid and elemental sulfur; the mixture containing arsenous acid and elemental sulfur mixes with 2 to 5 times (by mass) of water and then oxygen gas is introduced so that arsenous acid is oxidized into arsenic acid,and the reaction product is filtered to remove elemental sulfur and thus to produce an arsenic acid solution; and the arsenic acid solution is reduced by sulfur dioxide gas to arsenous acid with a lower solubility, the reaction liquid is distilled under a reduced pressure to produce a saturated solution of arsenous acid, the saturated solution of arsenous acid is cooled so that arsenous acid is crystallized and then filtered to produce a filter cake of arsenous acid, and the filter cake of arsenous acid is dried and pulverized to obtain an arsenic trioxide product The method has a short process flow, increases the recovery rate of arsenic, avoids the production of secondary pollutants, adopts simple equipment, greatly reduces the cost of arsenic recovery and is worthy to be widely applied

Method for preparing arsenic trioxide from arsenic sulfide waste

The invention discloses a method for recovering arsenic sulfide from arsenic-containing waste residue, which comprises the following steps: taking arsenic sulfide residue with the arsenic content of 7.1-16.8%, stirring and mixing with water, wherein the water content is calculated by 100-150mL/100g residue; evenly mixing, and gradually adding alkali at the temperature of room temperature-60 DEG C for carrying out leaching treatment, wherein the alkali content is calculated by 2.0-3.5g/g arsenic sulfide; further continuously maintaining the leaching process for 40-120 min after completing the addition of the alkali, and filtering; using water which is calculated by 50mL/100g arsenic sulfide residue for washing the residue step by step, merging filtrate and washing solution, using sulfuric acid with the concentration of 93-98% for neutralization, controlling the pH to be 9-11, filtering, further using the sulfuric acid with the concentration of 93-98% for neutralization till the pH is 1-3.5, adding sodium sulfide for leading the pH to be 2-4, then filtering, carrying out 2-3 times of repulping washing and filtering washing on sediment, obtaining secondary sediment, and drying for obtaining an arsenic sulfide finished product. The method can reduce the reaction temperature, shorten the leaching time and improve the recovery rate of arsenic.

Songlin Liu

Papers

Method for recovering arsenic sulfide from arsenic-containing waste residue