Study On Activation Technology Of Iron Tailings And Preparation Of Building Bricks

The iron tailings pile stock is increasing day by day,and the pollution degree to the environment is getting deeper and deeper.However,the comprehensive utilization rate of iron tailings in China is low,and the bulk utilization technology is not mature.At present,the process of making sintered bricks with clay has been banned,and there is a large market for building bricks.Fine-grained iron tailings are directly used for building bricks with low content and low mechanical strength.In order to make use of fine-grained iron tailings with large content and high efficiency,it is a good treatment method to activate them.Based on the activation method and theory of mechanical force,the activation process of iron tailings was systematically studied,and the activation mechanism was analyzed by specific surface area,scanning electron microscope and X-ray diffraction analysis.The influence of active tailings content,coarse aggregate content and other raw material ratio and additives on the mechanical properties of iron tailings brick,the optimal process conditions for preparing iron tailings brick were explored,and the technical and economic analysis was carried out on the field production.The research results show that:(1)After mechanical grinding,the reactivity of iron tailings has been improved to a certain extent.The reactivity of the tailings after grinding alone for 3h was 86.4%,and the activity index reached 91.71% after adding desulfurization gypsum as a grinding aid.(2)The mechanical force decreases the tailings' particle size,increases the lattice distortion degree,further strengthens the disorder degree,and increases the reactivity.After adding grinding aid,the agglomeration effect of fine iron tailings is reduced,further increases its specific surface area,and increases the lattice defect degree of iron tailings after grinding,further increases the reactivity.(3)When the molding water content is 20%,the active iron tailings content is 24%,the cement content is 36%,and the intermediate size iron tailings aggregate is 40%,the compressive strength of iron tailings brick is 39.93 mpa,and the flexion strength is 15.17 mpa.(4)Add agent can enhance the strength of iron tailing brick performance appropriately,calcium chloride,sodium sulfate and sodium silicate on the mechanical strength of iron tailing brick has a certain improvement,calcium chloride dosage was 1%,the compressive strength of iron tailing brick is highest,43.02 MPa,the flexural strength is 15.76 MPa,dosage of sodium sulfate was 1.5%,the compressive strength of iron tailing brick is highest,41.96 MPa,the flexural strength is 16.01 MPa,dosage of sodium silicate was 0.5%,the flexural strength of iron tailing brick is highest,16.19 MPa,the compressive strength of 40.43 MPa.A systematic study on the properties of iron tailings is carried out to explore the activation mechanism of fine-grained iron tailings,the influence of raw material content,additives and other conditions on the properties of building bricks of iron tailings,providing a path for the utilization of large content of iron tailings.Figure 26;Table 25;Reference 65...