【摘要】：聚渣劑作為鑄造生產(chǎn)過程中一種重要的輔料,從上世紀(jì)80年代開始,已經(jīng)廣泛的應(yīng)用到鋼鐵鑄造生產(chǎn)工程中。但是隨著我國(guó)鑄件產(chǎn)量逐年增加以及裝備制造業(yè)對(duì)鑄件性能要求的提高,單一的珍珠巖聚渣劑產(chǎn)品已經(jīng)不能滿足其性能要求。同時(shí)由于珍珠巖過度的開采加工,造成了大量珍珠巖尾礦的廢棄,嚴(yán)重影響生態(tài)環(huán)境。本課題設(shè)計(jì)不同預(yù)處理工藝參數(shù),采用SEM、DTA等試驗(yàn)設(shè)備,研究了烘干溫度、預(yù)膨化溫度、保溫時(shí)間對(duì)珍珠巖組織、膨脹倍數(shù)、失重率、容重等性能的影響規(guī)律;基于優(yōu)化的預(yù)膨化處理工藝,以珍珠巖尾礦為主要原料,通過工業(yè)試驗(yàn),研究開發(fā)新型復(fù)合聚渣劑的配方。研究結(jié)果表明:信陽珍珠巖中水有兩種存在形式,一種是吸附在珍珠巖表面的自由水;另一種是被玻璃質(zhì)包裹的結(jié)構(gòu)水;隨著烘干溫度的升高,珍珠巖的失重率逐漸增大,當(dāng)溫度高于450℃時(shí),珍珠巖的失重率穩(wěn)定在3.85%。隨著預(yù)膨化處理溫度的升高,預(yù)膨化后的珍珠巖失重率逐漸降低,膨脹倍數(shù)先增大后降低,容重則先降低后升高;預(yù)膨化處理后的珍珠巖表面出現(xiàn)微孔,斷面呈現(xiàn)層片狀,并且含有少量的空腔結(jié)構(gòu),且隨著預(yù)膨化溫度的升高,微孔的數(shù)量逐漸增多,空腔結(jié)構(gòu)的直徑逐漸增大,但是當(dāng)預(yù)膨化溫度達(dá)到1050℃時(shí),表面出現(xiàn)細(xì)長(zhǎng)的裂紋產(chǎn)生。隨著保溫時(shí)間的延長(zhǎng),預(yù)膨化后的珍珠巖失重率逐漸降低,當(dāng)保溫時(shí)間高于23s時(shí),失重率則趨于平穩(wěn);膨脹倍數(shù)呈現(xiàn)先升高后降低,容重則相反,先降低后升高。隨著保溫時(shí)間的延長(zhǎng),珍珠巖表面無裂紋,逐漸出現(xiàn)分布均勻、孔徑相差較小的微孔,斷面的空腔直徑則呈現(xiàn)先增大后降低的趨勢(shì),當(dāng)保溫時(shí)間高于23s的時(shí)候,部分空腔破碎,導(dǎo)致碎屑產(chǎn)生。因此,當(dāng)預(yù)膨化溫度為950℃,保溫時(shí)間為15s時(shí),膨脹倍數(shù)最大,為2.733,容重最低,為912kg/m3。與優(yōu)化預(yù)膨化處理后的珍珠巖相比,未經(jīng)預(yù)膨化處理以及隨爐加熱處理后的珍珠巖的容重較大,膨脹倍數(shù)較小,尤其是隨爐加熱處理后的珍珠巖,甚至出現(xiàn)顆粒萎縮的現(xiàn)象。通過對(duì)珍珠巖尾礦復(fù)合聚渣劑的研制及工業(yè)試用試驗(yàn),與單一珍珠巖聚渣劑相比,復(fù)合聚渣劑在鐵液中的鋪展效果、聚渣效果更優(yōu)異,且更易扒渣。優(yōu)化了珍珠巖尾礦復(fù)合聚渣劑配方,其主要組分為8%活性Si O2、4%活性Al2O3、4%水玻璃以及珍珠巖尾礦。
[Abstract]:As an important auxiliary material in casting process, slag-accumulating agent has been widely used in iron and steel foundry engineering since 1980s. However, with the increasing production of castings in our country year by year and the improvement of casting performance requirements in equipment manufacturing industry, the single perlite slagging agent can no longer meet its performance requirements. At the same time, due to the excessive exploitation and processing of perlite, a large number of pearlite tailings were abandoned, which seriously affected the ecological environment. The effects of drying temperature, pre-expansion temperature and holding time on perlite structure, expansion ratio, weight loss rate and bulk weight were studied by using SEM,DTA and other test equipment in this paper. The effects of drying temperature, pre-expansion temperature and holding time on perlite structure, expansion multiple, weight loss rate and bulk weight were studied. Based on the optimized pre-expansion treatment process, the formula of a new type of compound slagging agent was developed by industrial test with pearlite tailing as the main raw material. The results show that there are two kinds of water in Xinyang perlite, one is free water adsorbed on perlite surface, the other is glass-coated structural water. With the increase of drying temperature, the weight loss rate of perlite increases gradually. When the temperature is higher than 450 鈩，

本文編號(hào)：2464177