【摘要】：隨著煉鐵成本以及對(duì)外礦的依賴程度的不斷增加,在煉鐵過(guò)程中使用廉價(jià)低品位鐵礦石資源顯得尤為必要,尤其是對(duì)于一些遠(yuǎn)離港口的鋼鐵企業(yè)。新喀里多尼亞鉻鐵礦,TFe含量為32.58%,Cr2O3含量為29.46%,不適宜直接應(yīng)用高爐煉鐵和鉻鐵合金冶煉,以及磁化率比較低,難以通過(guò)正常選礦工藝提高鐵礦石品位,一直沒(méi)有得到有效利用。本論文以新喀鉻鐵砂礦為研究對(duì)象,在考查其基礎(chǔ)性能的基礎(chǔ)上,系統(tǒng)研究了其造球過(guò)程、焙燒過(guò)程及提高磁化率的工藝方法,為合理利用新喀鉻鐵砂礦提供理論支持。采用XRD和光學(xué)顯微鏡對(duì)新喀鉻鐵砂礦礦進(jìn)行了詳細(xì)研究,發(fā)現(xiàn)新喀鉻鐵砂礦以鉻鐵礦為主,鉻鐵礦顆粒多呈粒狀分布,結(jié)晶程度較好,結(jié)構(gòu)致密,晶粒粗大,氣孔較少;鉻鐵礦中的Cr3+常被Fe3+和Al3+置換呈類(lèi)質(zhì)同象結(jié)構(gòu),Fe2+常被Mg2+所置換,形成鎂鉻鐵礦和鐵綠鉻礦,導(dǎo)致鉻鐵選礦分離十分困難。新喀鉻鐵砂礦原礦粉球團(tuán)試驗(yàn)研究結(jié)果表明:膨潤(rùn)土配比達(dá)到2.0%時(shí),生球質(zhì)量才能滿足球團(tuán)運(yùn)輸和焙燒工藝的要求;適宜的成球條件為:膨潤(rùn)土配2.0%,礦粉粒度-200目80%,生球水分9.8%,煤粉配比2.0%、煤粉粒度-200目80%;適宜的干燥制度為:球團(tuán)粒度8~15mm,球團(tuán)礦層厚度200mm,干燥氣流速度1.0m/s,干燥溫度300℃和干燥時(shí)間10min。吊籃磁化焙燒不適用于新喀鉻鐵砂礦原礦粉球團(tuán)磁化焙燒工藝;用高溫反應(yīng)管在800℃隔絕空氣條件下對(duì)新喀鉻鐵砂礦原礦粉球團(tuán)進(jìn)行磁化焙燒40min,磁化焙燒后新喀鉻鐵砂礦原礦粉球團(tuán)礦采用一段磨礦、一次粗磁選和一次精選流程可以得到含TFe為58.67%的鐵精礦和含Cr2O3為46.96%的鉻精礦,TFe和Cr2O3的回收率分別達(dá)到77.06%和84.75%,鐵精礦和含鉻精礦的產(chǎn)率分別為46.23%和53.77%。
[Abstract]:With the increasing cost of ironmaking and the dependence of foreign mines, it is particularly necessary to use cheap and low-grade iron ore resources in the ironmaking process, especially for some steel enterprises far from the port. The content of TFe and Cr2O3 in New Caledonian chromite is 32.58% and 29.46% respectively. It is not suitable for blast furnace ironmaking and ferrochromium alloy smelting directly, and the magnetic susceptibility is relatively low. It is difficult to improve the grade of iron ore by normal mineral processing process, and has not been effectively utilized. In this paper, Xinka Chrome Iron Sand is taken as the research object, and on the basis of investigating its basic properties, the process of pelletizing, roasting and the process of improving magnetic susceptibility are systematically studied, which provides theoretical support for the rational utilization of Xinka Chrome Iron Sand. XRD and optical microscope were used to study the Xinka chromium iron placer in detail. It was found that the Xinka chromium iron placer was mainly chromium iron ore, the chromite particles were mostly distributed in grain shape, the crystallization degree was good, the structure was dense, the grain size was thick, and the porosity was less. The Cr3 in chromite was often replaced by Fe3 and Al3 with homogeneous structure, and Fe2 was often replaced by Mg2, resulting in the formation of magnesia-chromium iron ore and iron green chromium ore, which made it very difficult to separate ferrochromium ore dressing. The experimental results show that the raw pelletizing quality can meet the requirements of pelletizing transportation and roasting process when the ratio of bentonite reaches 2.0%, and the suitable pelletizing conditions are as follows: bentonite 2.0%, ore powder particle size 80%, raw ball moisture 8.8%, pulverized coal ratio 2.0%, pulverized coal particle size 80%, raw ball moisture 9.8%, pulverized coal ratio 2.0%, pulverized coal particle size 80%, bentonite 2.0%, pulverized coal particle size 80%, raw ball moisture 9.8%, pulverized coal particle size 2.0%, pulverized coal particle size 80%. The suitable drying system is as follows: pelletizing particle size 8 鈮，

本文編號(hào)：2501725