Study On Preparing Lightweight Ceramsite Using Leaching Residual Slag Of Lepidolite Ore

Jiangxi has rich mineral resources associated with lithium mica, and Jiangxi Gan Feng Lithium Industry Limited Company, the largest lithium processing enterprises of china, uses salt autoclaving method to extract lithium and preparates series of lithium salt. It is aimed at the development and utilization of Jiangxi lithium mica ore resources. But mineral extraction of lithium will produce a large of solid waste. It is the key to effectively utilizate the solid waste for mineral extraction of lithium.This paper takes lithium mica slag which comes from salt autoclaving method (hereinafter referred to as the pressure leaching lithium slag) of Jiangxi Gan Feng Lithium Industry Limited Company as main raw material, and mixs with clay and bentonite as raw material, then using orthogonal test to optimize formula and technological conditions. Finally, the ceramsite is fired, also its physical and mechanical performance is in line with level600excellent building material ceramsite of ordinary lightweight coarse aggregate according to the national standards GB/T17431.1-1998Lightweight aggregates and its test method.The results of orthogonal experiment indicate, the appropriate proportion scheme(mass percent) to prepare lithium slag ceramsite is:60%of pressure leaching lithium slag adds,10%of bentonite adds,30%of clay adds; The suitable calcination thermal system is:the preheat temperature chooses400℃, the preheat time chooses30min, the sintering temperature chooses1080℃, the sintering time chooses15min. The single factor experiments show that, with the sintering temperature increases, the cylinder compressive strength and bulk density of lithium slag ceramsite increase first and then decrease. When sintering temperature is1050℃, the cylinder compressive strength of lithium slag ceramsite is maximum. And when sintering temperature is950℃, the bulk density of lithium slag ceramsite is maximum. With the sintering temperature increases, water absorption rate do not change significantly in the early stage, but after the temprature of1000℃, water absorption rate is sharp decline, when sintering temperature is1100℃, water absorption rate is the least. X ray diffraction analysis shows that, the phase of lithium slag ceramsite is mainly quartz and mullite, it also contents a little anorthite, hematite and a certain number of vitreous; Scanning electron microscopic observation reveals, the surface of ceramsite is smooth and contenting small hole, and the interior contains a large number of uniform and less connected cellular, this structure makes lithium slag ceramsite with characteristics of light-weight, high-strength and low water absorption rate. Thus, lithium slag ceramsite owns properties of heat insulation, sound insulation and thermal insulation.The using of pressure leaching lithium slag is high volume amounted to60%of the proportioning of raw materials. So many leaching slags generated by lithium extraction can be utilized, making mineral lithium extraction completely realize clean production. It is very important to apply this project for the high efficient utilization of Jiangxi lithium mica ore resources, energy saving and environmental protection, its social effect is also very obvious. Technical and economic analysis show that, due to the large number of of industrial waste residue is utilized, it not only can reduce the raw material cost, but also can enjoy preferential tax policies of country, thus, it can achieve remarkable economic benefits.