Method for preparing magnesium-oxy-chloride cement by utilizing chromium slag produced through salt sub-melting technology

Abstract

The invention provides a method for preparing magnesium-oxy-chloride cement by utilizing chromium slag produced through a salt sub-melting technology. The method is characterized in that based on the characteristic that the chromium slag produced through the salt sub-melting technology is rich in magnesium oxide, the chromium slag can be used for replacing a part of magnesite light burning powder, thereby reducing the preparation cost of the magnesium-oxy-chloride cement; toxic hexavalent chromium in the chromium slag is reduced by utilizing ferrous iron, thereby eliminating the potential safety hazard; chromium slag produced through the salt sub-melting technology is rich in iron and can generate ferric hydroxide gel when used for preparing the magnesium-oxy-chloride cement, so that the compactness of products can be improved and then the wear resistance and the strength of the products can be further increased; and a modifier is added so as to improve the properties of the products, obtain a good water-resisting effect and eliminate the defects that the products are rimed and halogenated easily. During the preparation of the magnesium-oxy-chloride cement by utilizing the chromium slag produced through the salt sub-melting technology, neither strong acid nor strong base is involved, the method is carried out at normal temperature and normal pressure, the requirements on equipment materials are not high, the utilization rate of raw materials is high, the technological process is simple, and the method is a novel method for preparing the magnesium-oxy-chloride cement and recycling the chromium slag.

Description

technical field [0001] The invention relates to a method for preparing magnesium oxychloride cement and recycling chromium slag, in particular to a method for preparing magnesium oxychloride cement by using the chromium slag produced by a sub-molten salt process as a raw material, and realizing resource utilization of the chromium oxychloride. technical background [0002] The sub-molten salt process uses potassium hydroxide and chromite as raw materials to produce chromium oxide green. After a series of treatments, the chromium slag produced still contains hexavalent chromium and has a high content of magnesium, making its resource utilization a problem. At present, the treatment methods of chromium slag can be roughly divided into two categories: "source treatment" and "end treatment". The idea of ​​"source treatment" is to reduce the generation of chromium slag through new methods and new processes, which belongs to clean production and has not yet solved the problem fund...

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Problems solved by technology

[0004] However, the shortcomings of magnesium oxychloride cement are also obvious: (1) poor water resistance, the strength of general magnesite products is reduced by 70-80% after soaking in water for 28 days; Large water droplets appear, or even water droplets flow; (3) Improper ratio or too high active magnesium oxide in raw materials will cause excessive reaction and concentrated heat release, resulting in warping and deformation of the product; (4) hardened body cracks, manifested as The heat release is large, the condensation is too fast, the early strength develops quickly and the later strength is low, and it swells into fragments when it meets water; longer time

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