Study On Modified Manganese Slag Coated With Polymer And Its Application In Composite Thermal Insulation Mortar

Water quenching manganese slag is a kind of bulk industrial waste that manganese-iron alloy or silicon manganese alloy discharge after the quenching process of water quenching in the process of blast furnace smelting.In recent years,the resource utilization of waste slag emissions when the manganese series products are manufactured in the steel industry is low,resulting in most of these waste slag was piled outdoors for a long time,the consequence bring local enterprises and government burden as well as damage to the environment.This paper is based on the project of Guangxi Natural Science Foundation:Study on pore structure regulation and thermophysical properties of low shrinkage thermal insulation mortar(2014GXNSFAA118314).In view of low resource utilization problems of water quenching manganese slag,carried out the research on polymer coated and modified manganese slag and its application in composite thermal insulation mortar.In this paper,mainly study the effect of coated and modified solution made of styrene-acrylic emulsion and silicone hydrophobic agent on specific absorption of quality of water quenching manganese slag.In the test,the mother liquor of the styrene-acrylic emulsion and the silicone hydrophobic agent was mixed with water to dilute to different concentrations.Sprayed with water spray-like modified solution on the surface of water quenching manganese slag by high-pressure spray gun,dried by warm air and placed in the 60±5℃environment after drying to constant weight after the modified water quenching manganese slag.Studies have shown that when the concentration of coated and modified solution is 1:80(Modifier Mother liquor:water),and the mass ratio of styrene-acrylic emulsion and silicone hydrophobic agent was 1:3,the remediation of the manganese slag by the mixed solution is the best.At this point,the specific absorption of quality of water quenching manganese slag is5.34%,compared with the base sample decreased by 4.04%.In addition,the effects of the content of each component in the composite thermal insulation mortar on the mechanical properties and thermal performance were systematically studied.The results showed that the bending strength and dry density of the thermal insulation mortar is improved obviously when the dosage of modified manganese slag increased from0%to 100%,but the compressive strength will be reduced and the water absorption of the mortar is reduced.The best outer content is 75%.Manganese slag powder and fly ash replace50%of the cement,the effects of different ratio on the performance of the mortar were investigated by adjusting the quality ratio of the two.The experimental results show that the late gelling activity of manganese slag powder is more higher than fly ash,thermal insulation mortar’s compressive strength is the largest at the time of dosage of manganese slag powder and fly ash were 40%and 10%.The cement foaming agent introduces a large number of evenly distributed microbubbles in the thermal insulation mortar,effectively reducing the system’s dry density and thermal conductivity,to enhance the thermal insulation properties,at the same time,the intensity has declined drastically.So control the amount of cement foaming agent is 0.1%.The dry density is 436kg/m~3,thermal conductivity is 0.079W/(m·K),compressive strength is 1.1MPa,and linear shrinkage is 0.07%.The technique data of composite thermal insulation mortar conforms with the JGJ 253-2011“Technical specification for thermal insulating systems of inorganic lightweight aggregate mortar”typeⅡstandard requirements.Pore structure of water quenching manganese slag have been coated and modified was observed in terms of SEM and it is found that due to coated and modified solution can form a layer of solid waterproof film on the surface and pore wall of water quenching manganese slag,cut off the channel water enters into the interior of water quenching manganese slag,reduced specific absorption of quality.The hydration minerals and microstructure of cement-manganese slag powder-fly ash composite cementitious material were analyzed by means of SEM,results indicate that manganese slag powder and fly ash are involved in the secondary hydration of cementitious materials,producing more hydrated calcium silicate and ettringite and other products,improving the microstructure of the thermal insulation mortar.Compared with the local commercial insulation mortar,the cost of the thermal insulation mortar prepared by this test is low,and per cubic meter save 20%(per ton save 22%).The thermal insulation mortar has a strong competitive advantage in the market.