Method for treating manganese-containing wastewater generated during electrolytic manganese processing

Abstract

The invention discloses a method for treating manganese-containing wastewater generated during electrolytic manganese processing. The method comprises the following steps of: firstly, pretreating manganese-containing wastewater; adding sodium hydroxide to adjust the pH value to be 9.3+0.10; adding carbonate capable of undergoing a displacement reaction with Mn<2+> to generate a MnCO3 sediment; then, adding a flocculant and fully stirring, wherein the addition amount of the flocculant is 0.12-0.35 percent of the wastewater amount; leading the wastewater to enter a primary sedimentation tank, standing still, sedimenting MnCO3 and separating the MnCO3 from liquid; then, adding sodium hydroxide to adjust the pH value to 9.7+0.10; adding perhydrol and the flocculant; and leading the wastewater enter a secondary sedimentation tank and standing still to generate a Mn(OH)2 sediment; and adding an acid or alkali substance to adjust the pH value of the Mn(OH)2 sediment so that related indexes can reach an emission standard. The method disclosed by the invention is a production type treatment method for resource recycling, can be used for recycling manganese resources, has lower treatment cost and is beneficial to decrease of the costs of enterprises for treating the manganese-containing wastewater.

Description

technical field [0001] The invention relates to a treatment method for manganese-containing wastewater produced in the electrolytic manganese processing process, in particular to a treatment method for manganese resource recycling of the manganese-containing wastewater produced in the electrolytic manganese processing process. Background technique [0002] The electrolytic manganese plant will produce a large amount of metallic manganese (mainly Mn 2+ ) waste water, which mainly comes from electrolyte, circulating cooling water, ground washing water and equipment washing water, etc. After recycling these waste water, some waste water with relatively high manganese concentration will flow out of the production line for discharge, thus forming manganese-containing waste water that needs to be treated urgently . In addition, seepage water from the slag field is also a source of manganese-containing wastewater that cannot be ignored. At present, the moisture content of manganes...

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Problems solved by technology

[0004] In the prior art, the treatment of manganese-containing wastewater mainly contains the following methods. 1. Aeration treatment, in which gas is introduced into the manganese-containing wastewater to produce oxidation and other effects to make manganese precipitate. Its deficiency is mainly that the pH value is lower than At 9 o'clock, the reaction is slow and ineffective, and the effect is not ideal; 2, adding chlorine and hypochlorite oxidation, its deficiency is mainly invalid for organic manganese, and cannot oxidize organic manganese; 3, adding alkaline substances such as lime to adjust the pH value, its deficiency The main disadvantage is that lime can only be removed at PH=11-13, and the scope of reaction is narrow; 4. Catalysis is used to promote the reaction, but the catalyst is subject to more restrictions. Cu 2+ It can promote the oxidation of it by air; 2+ and Mn 2+ Effective, but can quickly oxidize the resin; 6. The way of introducing chlorine dioxide reaction can quickly oxidize manganese into insoluble manganese, but the cost is expensive; 7. Add manganese dioxide or potassium permanganate for reaction, which needs to be In the regenerated sand filter, excessive potassium permanganate is required, which is expensive and economical; 8. Directly put in potassium permanganate for reaction, which requires filtration and other treatment, and the treatment cost is expensive

The above treatment methods all oxidize soluble manganese to form insoluble manganese and precipitate it to achieve the removal effect. The product is insoluble matter in the form of manganese oxide; this kind of insoluble manganese oxide is difficult to recycle, and many companies do not have reasonable and effective methods. Using this product, it is directly transported to the slag yard for landfilling, which wastes this part of the manganese resource; the landfill treatment of the slag yard has produced water pollution problems, and has caused greater pollution to the environment, causing the discharge to exceed the relevant manganese resources. National standards; and the above-mentioned processing methods require more financial support, which also increases the financial burden of the enterprise and indirectly increases the processing cost

The treatment methods of manganese-containing wastewater in the prior art need to be improved in order to achieve better results, both in terms of meeting environmental protection requirements and in terms of up-to-standard discharge and recycling and resource utilization.

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