On January 10, 2024 China (Shanghai) Urban Wasteless-Summit Forum on Wasteless Application Technology and Practice in Construction Industry and Annual Meeting of Shanghai Sandstone Industry were held in Shanghai. Wang Peng, Director of Huaxin Aggregate Business Operation
of Huaxin Cement Co., Ltd., made a theme report on "Huaxin Aggregate Integrated Low Carbon Production Process", introducing the development of Huaxin Aggregate from four aspects: development process, mine stripping, production process and derivatives disposal.
According to reports, Huaxin entered the aggregate industry in 2006, which is the first cement enterprise in China. At present, Huaxin has 36 aggregate factories in China, and the mature factories and mines are all national, provincial and municipal green mines. Among them, Huangshi Huaxin Green Building Materials Industry Co., Ltd., with a total investment of 10 billion yuan, is located in Binjiang Industrial Park, Fuchi Town, Yangxin County, covering an area of more than 1800 mu, which is the largest in the world.
Wang Peng introduced that except Xinyang (gneiss), Huaxin aggregate mine is carbonate rock (limestone, dolomite), which has the characteristics of stable quality, no weathering layer, no radioactivity and strong workability. In terms of
mining and stripping, Huaxin Aggregate Mine is mainly composed of hillside open-pit mining and highway automobile transportation system, with a small amount of depression mining (Yangxin, Zhuzhou, etc.) and shaft adit transportation (Wuxue, Zigui, Zhaotong, etc.).
In view of the characteristics of high raw material particle size and low mud content of aggregate, centralized drainage (depression mining) and high level operation (shaft) are adopted to meet the requirements of production and operation. In terms of
production process, Huaxin actively builds digital factories, lays out AI safety monitoring system, online quality inspection system, HIAC system, etc., and continuously improves production efficiency. In terms of
derivatives disposal, Huaxin actively laid out green wall materials, using mine stripping waste soil, aggregate screening waste, aggregate washing and pressing mud cake, cement kiln ash, etc., to produce environmental protection brick products with high strength and freeze-thaw resistance.
Specifically, the production of aggregate needs to avoid mixing soil as much as possible. After the mine is stripped by classification, the pure soil is preferentially used for slope reclamation, and the surplus is used as cement silica-alumina ingredients. According to the difference of CaO content, the
soil with stone/undersize can be used as cement raw material if the content is greater than or equal to 45%, and the rest can be used for sand washing, water stabilization, etc.
In terms of stone powder, the stone powder with high CaO content is used for desulfurization; according to the different MgO content, it is used as cement raw material and double admixture; the stone powder with silt content and fineness meeting the requirements is used as mineral admixture for concrete and mortar.
