Comprehensive utilization of arsenic-containing sulfonic acid
Thread Content
The treatment of arsenic-containing sulfonic acids generally employs the lime-iron salt method, which yields good results. But the downside is a large amount of slag, resulting in high costs for slag site management. Do any of you have ways to reduce or eliminate slag formation? It would be even better if arsenic could be refined in the form of white arsenic. The specific values are as follows: As: 5~10g/L, Si: 1~5g/L, Fe: 1~5g/L
In the lime-iron salt method for treating polluted acid, arsenic is removed through sulfidation first, and then white arsenic is recovered from the arsenic residue. There are various processes for recovering white arsenic, and the operating costs vary greatly, depending mainly on the environmental protection requirements.
Hehe, go ask in the sulfuric acid technology discussion forum; you’ll be able to find answers there, hehe
At the current stage, it is difficult to recover useful metals from spent acid, and the production cost is high. The currently used process of arsenic removal via sulfidation, two-stage neutralization with lime milk, and the addition of iron salts can achieve the desired results. However, the treatment of acidic waste streams involves high costs, which necessitates the adoption of new treatment methods. In China, some universities have already experimented with the electrowinning method for treating arsenic-containing acidic waste streams, and its cost is lower than that of the sulfidation method, which will bring significant economic benefits to enterprises. Personally, I believe that with new technologies still not fully developed, there is much work to be done to reduce processing costs, and this work is closely related to the corporate structure and management level. Carrying out these tasks can significantly improve a company’s economic and environmental performance.
I would like to ask the expert upstairs about the general process of treating arsenic-containing waste acid using the electrowinning method. Thank you!
Reply to 1# yang*anghui: There is no good solution available at the moment. However, with such a composition, arsenic removal is not thorough; calcium arsenate re-dissolves, which is harmful to the environment. It is necessary to increase the amount of trivalent iron, so that the molar ratio of iron to arsenic reaches 4 – this is the safest method of treatment. After all, when engaging in production, one must be responsible for the environment. To reduce costs, limestone can be used in the first stage to neutralize the acid; of course, the issue of foam elimination must be taken into account. In the second stage, lime is used to raise the pH level and precipitate arsenic.
What kind of waste acid is this? With a silicon content of 1–5 g/l, it can’t be waste sulfuric acid, right? It’s hard to understand.
Based on my personal experience, the product obtained using the lime-iron salt method does not meet the **standards**; it contains a large amount of arsenic residue and is prone to causing secondary pollution. Wastewater like yours still needs to be treated via wet methods before being discharged
Shanghai Bande Environmental Protection Equipment Co., Ltd. possesses sulfurization-based arsenic removal technology, which has many advantages.
Reply 1# yang*anghui: How about using sulfur dioxide for reduction? White arsenic can be obtained in this way!