Extraction of Magnesium and Nickel from Nickel-Rich Serpentine with Sulfation Roasting and Water Leaching

Xiyun Yang,Lirong Tong,Lingyu Gao,Yingli Chen,Yulou Wu

doi:10.3390/met12020318

Abstract

Magnesium and nickel were recovered from nickel-rich serpentine through sulfation roasting and water leaching. The factors affecting the extraction percentages of Mg and Ni were discussed. Under the conditions of the ratio of acid to ore of 0.8:1 and roasting temperature of 650 °C for 120 min, 91.6% of Mg and 88.7% of Ni but only 4.8% of Fe were extracted. The roasting kinetics of Mg and Ni were investigated. The results showed that the roasting stage was governed by internal diffusion in the temperature range of 350–650 °C, and the activation energy of nickel and magnesium were different in the time ranges of 0–30 min and 60–120 min, with 17.45 kJ⋅mol−1 (0–30 min) and 14.12 kJ⋅mol−1 (60–120 min) for magnesium and 15.48 kJ⋅mol−1 (0–30 min) and 12.46 kJ⋅mol−1 (60–120 min) for nickel. The kinetic equations were obtained.

Highlights

Serpentine belongs to layered silicate minerals and exhibits a stable structure with the chemical formula [(Mg,Fe)3Si2O5(OH)4] [1,2]
When the roasting temperature was within the range of 200–650 ◦C, the extraction of magnesium and nickel increased with the temperature
A selective sulfation roasting process for nickel-rich serpentine using concentrated sulfuric acid followed by water leaching was proposed

Summary

Introduction

Serpentine belongs to layered silicate minerals and exhibits a stable structure with the chemical formula [(Mg,Fe)3Si2O5(OH)4] [1,2]. Many researchers have concentrated on the recovery of magnesium, nickel and other metals from serpentine through hydrometallurgical routes. Different leaching agents such as sulfuric acid, hydrochloric acid and organic acids have been systematically investigated [9,10,11,12]. 2T.hEexipmepriamctesnotaflconcentrated sulfuric acid amounts and roasting temperature as well as 2ro.1a.sMtinagtertiimalse for the extraction efficiency of Mg, Ni and Fe were studied in detail. The lower extraction rate at a higher temperature was possibly due to the decomposition of iron or nickel sulfate into their own oxides. Figguurree44. .TTheheffeefcftescotsf roofarsotiansgtipnagrapmaertaemrs:e(tae)rssu:l(fua)riscualcfiudraimc aocuindt,a(mb)oruoanstt,in(bg )termoapsetriantgurtee,manpderature, and ((cc)) rrooaassttininggtitmime.e

Roasting Mineralogy Analysis

Effect of Roasting Temperature

Effect of Roasting Time

Findings

Conclusions