本文選題：鐵尾礦 + 復(fù)合摻合料��； 參考：《武漢理工大學(xué)》2015年碩士論文

【摘要】：將鐵尾礦磨細(xì)作為混凝土摻合料已經(jīng)成為鐵尾礦利用的一種新途徑。本文針對(duì)鐵尾礦粉活性低、對(duì)混凝土力學(xué)性能及耐久性能影響不明確等問題,開展了以鐵尾礦為基料,以磷渣、石灰石為輔料制備鐵尾礦基復(fù)合摻合料(TPCA)的技術(shù)研究,并研究了摻TPCA復(fù)合摻合料混凝土的性能。運(yùn)用數(shù)學(xué)最小二乘法研究分析了不同粉磨時(shí)間下鐵尾礦粉及其28d抗壓活性指數(shù)之間的關(guān)系;引入有效粉磨時(shí)間Q(min),從細(xì)度組合、原料配比、粉磨工藝及助磨劑四個(gè)方面對(duì)TPCA的活性提高技術(shù)及粉磨能耗降低技術(shù)進(jìn)行了研究,并利用激光粒度分析、RRB方程擬合等手段研究了梯級(jí)粉磨順序、梯級(jí)粉磨時(shí)間對(duì)采用梯級(jí)粉磨工藝制備的TPCA的粒度分布特征及膠砂活性指數(shù)的影響。研究結(jié)果表明:鐵尾礦的活性隨著粉磨時(shí)間的增加,具有增長(zhǎng)不明顯的特性。梯級(jí)粉磨制得的TPCA體系的工作性能及力學(xué)性能均優(yōu)于單獨(dú)粉磨和混合粉磨;將易磨性較差而活性較好的磷渣預(yù)先粉磨有利于TPCA粉料中磷渣細(xì)顆粒含量的增加,提高其整體活性;合理的粉磨時(shí)間有助于提高TPCA粉料顆粒分布的均勻性,提高膠砂流動(dòng)度;適量的助磨劑三乙醇胺有助于提高TPCA粉料的細(xì)度,降低粉磨能耗。在Q=42.5min,原料配比鐵尾礦:磷渣:石灰石=6:3:1,三乙醇胺摻量為0.04%時(shí),利用梯級(jí)粉磨工藝制得的TPCA流動(dòng)度比為100%,28d抗壓活性指數(shù)為82%。采用TPCA配制了強(qiáng)度等級(jí)為C20~C55的預(yù)拌混凝土,并對(duì)比研究了摻TPCA與Ⅱ級(jí)粉煤灰、S95級(jí)礦渣粉復(fù)合摻合料混凝土的強(qiáng)度與耐久性。結(jié)果表明:摻入30%的TPCA可配制出C20~C55強(qiáng)度等級(jí)的混凝土,TPCA對(duì)混凝土強(qiáng)度的影響與與Ⅱ級(jí)粉煤灰相當(dāng),但低于S95級(jí)礦渣粉;摻入20~40%的鐵尾礦基復(fù)合摻合料的混凝土的抗碳化、抗氯離子滲透和抗凍等耐久性能,略低于Ⅱ級(jí)粉煤灰與S95級(jí)礦渣粉復(fù)合摻合料的的混凝土,但影響并不明顯。通過復(fù)合膠凝材料水化熱、漿體強(qiáng)度、X射線衍射測(cè)試(XRD)和掃描電鏡測(cè)試(SEM),對(duì)比研究了鐵尾礦粉和TPCA在復(fù)合膠凝材料水化硬化過程中的水化機(jī)理。研究表明:鐵尾礦粉自身具有微弱的水化活性,而TPCA的水化活性相比鐵尾礦粉則顯著提高,且其水化活性的發(fā)揮主要體現(xiàn)在水化后期。
[Abstract]:Grinding iron tailings as concrete admixture has become a new way of iron tailings utilization. Aiming at the problems of low activity of iron tailings powder and unclear influence on mechanical properties and durability of concrete, the technical research on the preparation of TPCA-based compound admixture of iron tailings with iron tailings as base material, phosphorus slag and limestone as auxiliary material is carried out in this paper. The properties of TPCA-doped concrete are also studied. The relationship between iron tailings powder and its 28d compressive activity index under different grinding time was studied by using mathematical least square method. The improvement of TPCA activity and the reduction of grinding energy consumption were studied in four aspects of grinding process and grinding aids. The step grinding sequence was studied by means of laser particle size analysis and RRB equation fitting. The effect of step grinding time on the particle size distribution and sand activity index of TPCA prepared by step grinding process. The results show that the activity of iron tailings does not increase obviously with the increase of grinding time. The working properties and mechanical properties of the TPCA system prepared by step grinding are better than those of single grinding and mixing grinding, and the pre-grinding of phosphorus slag with poor grindability and good activity is beneficial to increase the content of fine particles of phosphorus slag in TPCA powder and improve its overall activity. Reasonable grinding time can improve the uniformity of particle distribution and increase the flowability of cemented sand, and the proper amount of triethanolamine can improve the fineness of TPCA powder and reduce the grinding energy consumption. When the ratio of iron tailings: phosphorus slag: limestone is 6: 3: 1 and triethanolamine is 0.04, the flowability ratio of TPCA prepared by step grinding process is 100 / 28d and the activity index of TPCA is 82 / 28d when the ratio of iron tailings to phosphorus slag: limestone is 6: 3: 1 and the amount of triethanolamine is 0.04. The premixed concrete with strength grade C20C55 was prepared by TPCA, and the strength and durability of the concrete mixed with TPCA and grade 鈪，

本文編號(hào)：2044492