Experimental Study On Preparation Of Cement And Steaming-free And Burning-free Brick By Using Converter Slag

Converter slag is the inevitable by-product of steel-making process, the output of converter slag increases with the increment of the steel output. However, the recovery method and technology of converter slag is laggard. Therefore, how to use the converter slag more effectively has important significance in promoting the continuous and efficient development of the iron and steel industry.In this paper, converter slag, iron tailings and fly ash are taken as raw materials for the preparation of cement and steaming-free and burning-free brick. The components and microstructures were examined by element analyzer, X-ray diffraction (XRD) and Microscope.Firstly, converter slag was used as the mainly raw material for the preparation of cement and steaming-free and burning-free brick. The sintered method is adopted to prepare the Portland cement. And the mechanical capabilities are determined. The effect of converter slag as raw material on cement's capabilities and mechanism is analyzed. The results showed that:①converter slag was used for raw material, the best experimental scheme for preparing Portland cement was converter slag 3%, iron tailings 3.5%, fly ash 16% and limestone 77.5%, respectively; and at this time, IM=1.58,KH=0.88,SM=2.11. Burning craft was at 1350℃keeping 2h; the cooling quomodo was fast cooling in the water. The amount of adding gypsum was 3.5% of cement.②converter slag was used for the additives. The compressive strength of cement at variable ages didn't go down obviously when adding 6% and 10% converter slag; the compressive strength of cement at 28 day went down from 73.28Mpa to 47.83Mpa when the adding converter slag from 0% to 15%, the extent of decrease was 34.7%. Length change of Le chatelier was from 1.5mm to 3.5mm; the setting time prolonged while adding more converter slag; although adding converter slag led to the change of mechanical capabilities, the product satisfied the standard of GB and belonged to the eligible product.Secondly, The new-style wall material:Steaming-free and burning-free brick making use of converter slag,iron tailings,fly ash as primary material was prepared. The orthogonal experiment is used to determine the successive relationship, such as the effect of fly ash, lime, cement and gypsum on the compressive strength. Then the replacement test of converter slag and experiment of the decreasing cement's amount to determine the best scheme of steaming-free and burning-free brick are studied. At the same time, the capabilities of steaming-free and burning-free brick are determined. The effect of the molding tension and curing time on the compressive strength of steaming-free and burning-free brick are analyzed, also the mechanism of strength form. The result showed that the effect of fly ash,lime,cement and gypsum on the compressive strength in the orthogonal experiment was:cement> gypsum> fly ash> lime. It showed that the substitute experiment:the compressive strength of steaming-free and burning-free brick was improved as the adding of 40% converter slag in the replacement test of converter slag. Compressive strength was 15.7Mpa and 34.9Mpa, respectively. It showed in the decreasing of cement's amount in experiment:compressive strength of steaming-free and burning-free brick was 16.8Mpa while the amount of cement decreasing to 2%, already attained MU15. Compressive strength increased with the increment of cement. The highest compressive strength was 35.0 Mpa. Therefore, steaming-free and burning-free brick of MU15-MU25 could be made by using the different scheme; When steaming-free and burning-free brick were used for the structural material, considering all the influencing factors synthetically, the best experimental scheme was that:converter slag 26.8%, iron tailings 34.2%, fly ash 10%, cement 16%, lime 12% and gypsum 1%, respectively; the molding tension was 20Mpa; Average density was 1.96×103 kg/m3. Effects of different additives calcium lignosulfonate, high range water reducing agents, CaCl2, Na2SO4 on compressive strength have been investigated, and its mechanism is analyzed. It showed that the effect of high range water reducer on compressive strength was remarkable. The addition of 1%cement led to the increase of the rate of compressive strength, namely 18.7% for 7 day. The rate of the compressive strength increment was 6.9% for 28 day. Steaming-free and burning-free brick endured 15 freeze-thaw circles. The average losing rate of the compressive strength was 1.96%. The average losing rate of weight was 0.67%. The freeze-proof character is good. The average drink rate was 9.7%. These showed that the porosity is low and the internal quality was well; the compressive strength of steaming-free and burning-free brick increased with the increment of molding tension; and the compressive strength of steaming-free and burning-free brick increased with the increment of curing time.