Improvement in pelletization of Brazilian specularite by high-pressure roller grinding
-
摘要: 采用高壓輥磨技術預處理鏡鐵礦,對強化其球團工藝及機理進行了研究.掃描電鏡觀測證實,通過優化高壓輥磨閉路流程的循環負荷,巴西鏡鐵礦的表面形狀及比表面積得到改善,成球性得到明顯提高.以70%鏡鐵礦配加30%磁鐵礦為原料,采用71%高壓輥磨產品返回方式處理后,在添加2.4%的膨潤土、造球時間15 min及造球水分8%的條件下,生球各指標與同配比未經高壓輥磨處理的相比均有大幅度提高,其0.5 m落下強度達到4.5次,單球抗壓強度10.25 N,爆裂溫度455℃;生球在預熱溫度1 050℃、預熱時間10 min,焙燒溫度1 280℃、焙燒時間12 min的條件下焙燒,成品球單球抗壓強度達到2 690.88 N,滿足球團生產的要求.Abstract: The processing and mechanism of the improvement in pelletization of Brazilian specularite by high-pressure roller grinding (HPRG) were investigated. SEM observations show that after being pretreated by HPRG in a closed flow path at an optimized cyclic loading, the specific surface area of Brazilian specularite increases greatly and its ballability is dramatically improved. The pellet feed composed of 70% specularite and 30% magnetite was pretreated by HPRG at 71%-product cyclic loading in a closed flow path, mixed with 2.4% bentonite and balled for 15 min under the 8% moisture. Experimental results show that all indexes of green pellets are much higher than those of the pellets made of the same feed without the pretreating. The drop number is up to 4.5 times from the 0.5m height, the compression strength is 10.25 N per pellet, and the thermal shock temperature is 455℃. The compression strength of fired pellets was tested up to 2690.88 N per pellet by preheating at 1050℃ for 10 min and by roasting at 1280℃ for 12 min, which meets the demand of strength for commercial pellets.
-
Key words:
- high-pressure roller grinding /
- specularite /
- magnetite /
- pellets
-

計量
- 文章訪問數: 273
- HTML全文瀏覽量: 68
- PDF下載量: 11
- 被引次數: 0