The Application Research On Making Autoclave Aerated Concrete Building Blocks Using Cangshan Iron Ore Tailings

Sino Steel Group Shandong Mining Co.Ltd.is located in Cangshang of Shandong province.Cangshan iron ore is rich in resource reserves,but is a low grade saddle type mine.The characteristics of tailings production which is produced in the mineral processing are fine granularity,high silicon content,and difficult and high cost for recycling.Some part of the tailing production is used to fill the mined out hole of underground mine,the other part is discharged into the temporary waste tailings storage pit on the earth surface.It will case soil when the waste tailings storage pit is full of tailing production.However,it will be very expensive to construct and manage the tailings discharging project.Because the procedure of this project includes the land requisition,waste tailings discharging and casing soil,and it will cost a lot money in every procedure.In order to solve the problems dealing with the iron ore tailings,and better construct harmonious green mines,a research program was proposed to produce autoclave aerated concrete building blocks using Cangshan iron ore tailings by comprehensive analysis the iron ore tailings and its utilization methods.The purpose of this research program is to solve the emission problem of iron ore tailings and save the construction cost of waste tailings storage pit and casing soil.This project will be carried out and it can not only improve the ecological environment around the mining area,but also can make full use of the iron ore tailings resources reasonably.In recent years,the degree of green and environmental protection of construction has become an important index to distinguish different quality of construction work with the development of our country’s construction industry.The implementation of environmental protection and green engineering has become a common practice.The main raw material of non bearing wall has been changed from clay brick and concrete block into autoclaved aerated concrete block.The new wall materials of autoclaved aerated concrete block which can realize energy saving,land saving,effective usage of waste materials is not only the prerequisite of industrialization and modernization of construction industry,but also is the demand of coordinated development of our country for the society,environment,resources and economy.In this paper,it is researched about the comprehensive utilization of Cangshan iron ore tailings in Shandong Steel Group Mining Co.Ltd.,and is carried out through experiments for the research of autoclaved aerated concrete block,and the result shows that autoclaved aerated concrete block produced by iron ore tailings can meet the requirements of relevant national standards and norms.The feasibility of making autoclaved aerated concrete block with iron ore tailings is studied In the last,and the main conclusion of this research are as follows:1).To illustrate the necessary of making autoclaved aerated concrete block,the serious harm to current environmental caused by the tailings piled up in the open air is analysed and along with it the cost is increasing for the mining enterprise to deal with the tailings disposal.2).The result through test shows that the optimum content of gypsum is 3% to make autoclaved aerated concrete block for Cangshan iron ore tailings.3).The best ratio is 70:17:3:10 through test for iron tailings: Lime: Gypsum:cement,and the product of autoclaved aerated concrete block can meet therequirements of relevant national standards and norms for Cangshan iron ore tailings.4).The development planning,industrial policy and industryadmittance areanalyzed for the project of aerated concrete block.The project must meet the mediumand long term development plan of state or province and also comply with the relevantprovisions of the national comprehensive utilization of construction waste whichbelongs to the projects encouraged by the state.5).The market demand for the autoclaved aerated concrete block project isanalyzed.The autoclaved aerated concrete block is the energy-saving building wallmaterials in line with national key development and has the effect of energy savingand environmental protection,and will become the first choice of wall materials.6).The economic effect is evaluated for the project of autoclaved aerated concrete block of annual output of 300,000 m3.The total investment of the project is about 194,000,000 yuan.And the annual consumption of tailings will be 129896.9 tons.The annual profit will be 125,880,000 yuan,the investment return rate is 64.89%,and the investment recovery period is 1.5 years.In summary,the autoclaved aerated concrete block production line with an annual output of 300,000 m3 is feasible.