Abstract Rotary Kiln - Electric Furnace (RKEF) process is the most commonly used pyrometallurgical technique for processing nickel laterite ores and is mainly suited for saprolite deposits. Sulfur is one of the harmful elements in crude ferronickel obtained via the RKEF process. Typically, laterite ores contain insubstantial sulfur content; hence, it is hypothesized that most of the sulfur in crude ferronickel originates from the coal added as the fuel and the reductant during calcination in the rotary kiln. This study investigates the role of sulfur content of rotary kiln fuels on the composition of the calcine. The calcination-partial reduction experiments were conducted at 900 °C for a 2-h residence time. Various reducing gas mixtures representing combustion products of rotary kiln fuels (e.g., coal) were contacted with the ore. At constant PCO, the sulfur content of the calcine increases linearly with an increase in PSO2 in the input gas mixture. Similarly, at fixed PSO2, the percentage of sulfur in the calcine and the percentage of sulfur deportation increase with PCO. However, an exceptional case is observed at PSO2 = 0 atm in the input gas mixture; the sulfur content and sulfur deportation slightly decrease by increasing PCO in the input gas. The sulfur content and the percentage of sulfur deportation drop at a lower input flow rate of the reducing gas mixtures.

中文翻译：

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回转窑燃料中硫对红土镍煅烧的影响

摘要 回转窑-电炉（RKEF）工艺是处理红土镍矿最常用的火法冶金技术，主要适用于腐泥土矿床。硫是通过 RKEF 工艺获得的粗镍铁中的有害元素之一。通常，红土矿石含有少量硫；因此，假设粗镍铁中的大部分硫来自在回转窑中煅烧期间作为燃料和还原剂添加的煤。本研究调查了回转窑燃料的硫含量对煅烧物成分的影响。煅烧-部分还原实验在 900 °C 下进行，停留时间为 2 小时。代表回转窑燃料（例如煤）的燃烧产物的各种还原气体混合物与矿石接触。在恒定 PCO 下，煅烧物中的硫含量随着输入气体混合物中 PSO2 的增加而线性增加。类似地，在固定 PSO2 下，煅烧中硫的百分比和硫排出的百分比随 PCO 增加。然而，在输入气体混合物中 PSO2 = 0 atm 时观察到一个例外情况；通过增加输入气体中的 PCO，硫含量和硫排出量略有降低。在还原气体混合物的较低输入流速下，硫含量和硫排出百分比下降。通过增加输入气体中的 PCO，硫含量和硫排出量略有降低。在还原气体混合物的较低输入流速下，硫含量和硫排出百分比下降。通过增加输入气体中的 PCO，硫含量和硫排出量略有降低。在还原气体混合物的较低输入流速下，硫含量和硫排出百分比下降。