The Preprocess Of Acid Leaching Manganese Slag And The Preparation Of Non-fired Bricks

Abstract:So far, the production of electrolytic manganese industry at home and abroad is generally disposed of acid leaching manganese slag by the way of releasing into tailing pond. On one hand it takes up a lot of land resources, on the other hand there are huge security potential accident. The comprehensive utilization and dispose of acid leaching manganese slag have caused a lot of attentions. Nowadays, due to the high content of dehydrate gypsum in the manganese slag, it was often used as cement retarder instead of gypsum through calcinations process. It leads to the secondary pollution of environment during the calcinations. The manganese slag contains (NH4)2SO4, which can be discomposed to produce the acidic gas such as SO2. In order to avoid the secondary pollution during the acid leaching manganese slag calcinations, this paper aimed to put forward a new green process for the utilization of manganese slag. Active material was dissolved by the preprocessing of manganese slag with lime. After addition of a certain amount of cement and aggregate, the mixture was stirred well and molded by pressure to produce the non-fired brick. This method can avoid using calcinations process of the manganese slag, which is a true green industry.The study shows that the main object of manganese slag are SiO2and Ca2SO4·2H2O, also contains a small amount of A12O3、MnSO4、(NH4)2SO4. The acid leaching manganese residue non-burnt is developed by using electrolytic manganese residue-lime-cement as the main material, added with certain quantities of aggregates-river sand and molded by pressure. Orthogonal experimental method was used to determine the optimal ratio of material. The factors affecting the strength of product are analyzed, such as plastic sand ratio and molding pressure. On the basis of testing the compressive strength of it and with doing XRD and Scanning Electron Microscopy (SEM) have showed the mechanism. The optimal molding pressure is25MPa, The optimum compositions of raw materials have been recommended as the following:electrolytic manganese35%, sand45%,lime7%,cement13%,water-solid ratio0.14；he optimum amount of admixture is:trolamine0.01%,calcium chloride1.5%,sodium sulfate1.0%,calcium lignosulfonate0.3%.