(中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 配加鈉鹽焙燒可改善紅土鎳礦的還原−磁選效果，顯著提高磁性產(chǎn)品的鎳、鐵品位及回收率。通過(guò)熱力學(xué)計(jì)算，并結(jié)合X射線衍射、光學(xué)顯微鏡以及環(huán)境掃描電鏡分析，對(duì)硫酸鈉和碳酸鈉作用下紅土鎳礦的還原行為進(jìn)行研究。結(jié)果表明：鈉鹽在紅土鎳礦還原焙燒過(guò)程中，可以破壞硅酸鹽礦物的結(jié)構(gòu)，有利于鎳的還原富集。碳酸鈉強(qiáng)化鎳還原的能力強(qiáng)于硫酸鈉的，硫酸鈉則因還原過(guò)程中形成的硫具有降低鎳鐵金屬顆粒表面張力的作用，因而其促進(jìn)鎳鐵顆粒聚集長(zhǎng)大的能力明顯高于碳酸鈉的，且硫酸鈉作用下FeS的形成也有利于提高鎳的品位。所以，硫酸鈉和碳酸鈉的共同作用下可獲得高鎳品位的磁性產(chǎn)品及較高的鎳回收率。
關(guān)鍵字: 紅土鎳礦；鈉鹽；還原焙燒；鎳鐵
nickelferous laterite ore in presence of sodium salts
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The sodium salts are able to enhance the reduction roasting-magnetic separation of the laterite ores significantly and improve the content and recovery of nickel and iron of magnetic product. The reduced behaviors of saprolitic laterite in the presence of sodium sulfate or sodium carbonate were investigated by using thermodynamical cal, culation, X-ray diffractometry, optical microscopy and environmental scanning electron microscopy. The results show that sodium salts are able to enhance the reduction and beneficiation of nickel. The sodium carbonate is more effective than the sodium sulfate to reduce nickel locked in forsterite. However, the sodium sulfate is capable of facilitating the growth and coalescence of ferronickel particles because sulfur formed during the reduction of sodium sulfate, diminishing their surface tension, as well as improving the separation of nickel from iron by forming FeS and inhibiting the complete reduction of iron. Thus, a ferronickel material with high nickel content and high recovery of nickel can be obtained in the presence of both sodium sulfate and sodium carbonate.
Key words: laterite ore; sodium salts; reduction roasting; ferronickel
