| With the large-scale open-pit mine into underground mining and environmental and ecological protection more strict,filling mining as a green and environmentally friendly method,is widely used in colored,gold and other precious metal mines,and gradually promote the use of iron ore mining and coal mines.At present,the cement gelatin material as the main domestic filling method,because the body strength is low,slurry resistance is big,and the filling cost is high,thus it brings serious economic pressure for iron ore filling.In particular,the sluggish international steel market makes the application of iron ore mining technology difficult.Anshan Iron and Steel Group Corporation "Research and application of large-scale underground mining core materials" as the basis,the paper carries out the following study:(1)Using Anshan Iron and Steel and the industrial waste such as slag,steel slag,desulfurization gypsum,and desulfurization ash,study new filling cementing materials for iron ore full tailings.(2)According to the physical and chemical properties of the full tailings in Anshan Iron and Steel Mine,the thick mechanism and technology of high-efficiency and low-cost are studied to realize the safety and low-cost mining and the utilization of solid waste(3)Full tailings thick and high concentration of slurry pipe transmission technology,is the core technology to achieve large-scale production of iron ore.Thus carrying out full-tail mortar thick test and cementing slurry rheological properties and pipeline transport characteristics of L pipe test,to provide theoretical support for full tail mortar thick technology and optimal design of pipeline filling system in Anshan mine.The main research results obtained in this paper are as follows:(1)The quality and activity of slag and steel slag in Anshan meet the requirements of development and utilization of cementitious materials,but the high grinding cost and the potential microexpansibility,so the application is limited.(2)Based on the slag powder as the main material,A,B and C are used as the activator materials to develop two kinds of composite activator binder materials.The formulation of salt-based compound activator is A 4%,B 19%,C 0.5%and slag powder 76.5%.The compressive strength of 7d and 28d of tailing cementation is 0.5MPa and 3.89MPa respectively The strength is 22%and 2.0 times of the cemen,and the cost is 46.5%lower than that of 32.5 cement.The formulation of alkali-based compound activator formula is A 11%,B 4%,C 0%,slag powder 85%.(3)The optimum formulation of slag-steel slag mixed binder is obtained by orthogonal test of slag-steel slag "A-B-C" compound activator.On the basis,the BP neural network model was established by using the experiment as the learning sample.The optimal ratio was 12%for A,4%for B,1%for C and 26%for steel slag powder,and the cemented filling strength meets the mining requirements.(4)Aiming at the physical and chemical properties of the full tailings in Anshan Iron and Steel Mine,the thick technology and mechanism are carried out.The anionic flocculant is selected,and the molecular weight,single consumption and concentration are determined as follows:When the full tailing concentration is 20%,the weight is 15000 flocculan,the unit consumption is 38-40g/t,and the concentration is 0.34%;the settling rate is 20.5cm/min or 12.3m/h,the underflow limit concentration is 70.8%,and the critical mass fraction is 57.3%;when the full tailing concentration is 35%,the anionic molecular weight is still 15000 flocculation,the unit consumption is 103?107g/t,and the flocculant concentration is 0.32%;the sedimentation rate is 4.17cm/min or 2.5m/h,the underflow limit is 71.12%,and the average concentration of bottom flow is 63.3%.(5)Rheometer test and filling slurry rheological parameters of L tube test are carried out.Test and study the slurry parameters and the pipeline resistance.The results are as follows:when the ratio of filling material and aggregate is 1:10?1:6 and the slurry concentration is 66%?72%,the viscosity of filling material is lower than cement,and the flowability is good,which is helpful to improve the filling slurry concentration.When a new type of cementing material is adopted,the radio of filling material and aggregate and concentration have an impact on yield stress,viscosity coefficient and transmission resistance.The slurry concentration is the most significant.When the slurry concentration is the same,with the increase of the cementing ratio,the increase effect of slurry flow is very limited compared with the decrease of pulp concentration.Therefore,it is not economical to improve the fluidity of filling paste by improving the cementing ratio.Under normal circumstances,the reasonable mortar ratio is determined according to the mining strength requirements. |
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