Study Of The Gold Slag-red Mud Glass-ceramic

In recent years, with the development of the gold and aluminum industry, a large number of gold slag and red mud were thrown away, caused great influence to the enterprise and environment. In this article, these two kinds of by-product were used as raw materials, and add a certain amount of additives to make gold slag-red mud glass-ceramic by melting method, witch to find a new way to solve the problem of environment pollution made by gold slag and red mud.In this experiment, total content of gold slag and red mud was designed as 85%by the chemical component of two by-products and the pre-exploratory, in which the percentage of gold slag was 50%,55%,60%,65% and 70%. The heat treatment process of glass-ceramic was determined by differential thermal analysis (DTA), and to analyze the phase composition and microstructure of glass ceramics, the XRD and SEM were adopted in the experiment. Effects of gold slag and red mud content, heat treatment system on the physical and chemical properties of glass ceramics were studied to analysis the relationship between microstructure and macro properties, and the best proportion (55% gold slag and 30% red mud) of the gold slag-red mud glass ceramics and corresponding heat treatment system were determined.The results showed that, the phases of gold slag-red mud glass ceramics were ilmenite and pyroxene, had never changed when the content of gold slag and red mud changed. With the increase of gold slag, pyroxene phase increased and ilmenite phase decreased:when the content of gold slag was less than or equal to 60%, the main crystal phase was ilmenite and the second was pyroxene; and when the content was greater than or equal to 65%, the main crystal phase became pyroxene and the second became ilmenite. After the heat-treatment, the granular crystal were precipitated and which size between 0.2-0.5μm. With the increase of gold slag, the glass phase increased and the crystallization ability reduced gradually. With the increase of gold slag addition, the flexural strength increased firstly and then decreased, the acid resistance increased and the alkaline resistance properties reduced. When gold slag adding amount was 55%, the compactness of the glass ceramics was preferable, and the mechanical performance was optimal and the flexural strength was able to 161MPa.In this paper, glass ceramics prepared by 55% gold slag and 30% red mud significantly discussed for the influence of heat treatment system on the phase compositions, microstructure and properties. The results showed that:the main crystal phase was ilmenite and the second was pyroxene, and did not changed with the heat treatment temperature and time. With the heat treatment temperature elevation or the time extension, the grain grow up and became uniformed, thus to improve the properties of the glass ceramics. But high heat treatment temperature or long heat treatment time can make the grain grow bulky or even caking, and defects of cracks and holes appeared in glass ceramics, which affected its properties. With the heat treatment temperature elevation or the time extension, the flexural strength and chemical stability increased firstly and then decreased, and the density increased and converged eventually. The results showed that, when gold slag content was 55% and red mud content was 30%, the flexural strength was the highest, which was 167 MPa and the heat treatment temperature of 940℃ and 2h heat treatment time.