Processing of Nickel Ores
Nickel is a fifth-order element, which is among the most abundant on Earth. The total amount of its resources is estimated to be around 350 million tons around the world.Ni-containing ore that is mined in more than 25 countries is present as sulphide and laterite-type ore deposites, which are also a major source of cobalt. It is mainly used to produce the stainless steel at a rate of 69 percent. The higher energy density and greater storage capacity is reckoned with a significant role in the battery industry.
Their mining costs are high since these resources are located deep underground. So, the recovery methods of Ni play a critical role in terms of commercial viability and sustainability.
Sulphide ores are processed by pyrometallurgical. Laterite ore is three main layers which are limonite, transition and saprolite. The pyrometallurgical methods are applied in the production from the saprolite layer. The limonite and transition layers are processed by hydrometallurgical due to the low iron content.
Mainly, two hydrometallurgical processes are improved for the recovery of base metals. One of them is high pressure acid leaching where occur in an autoclave. The biggest problem in economical aspect with this process is high energy requirement due to high temperature and pressure. For this reason, the HPAL is suitable when the plant is very large and heavy. The other hydrometallurgical method is atmospheric acid leaching which is conducted at a low temperature and requires open vessels avoiding the need of expensive autoclaves.
After the leaching, solvent extraction as a seperation method is a common process in the mining industry because of feasibility for plants that have small to medium capacities and similar quality to the mine site. Additionally, the low capital and operating costs of SX plant is the most economic way to obtain Ni by taking into consideration the developments in SX extraction equipment design and engineering, commercial availability of new solvent extraction reagents. Besides these features, closed-loop circulation of chemicals used in extraction like extractant, diluents is the essential phenomena to sustain an ecofriendly operation.
Proses Makina Company designed the integrated extraction system including leaching reactors, mixer settlers, sedimentation tanks, wastewater purification system for recovery of Ni with a special solvent. The company provides the efficient industrial solutions on high purity to its customers by carrying out R&D projects on development of solvents.