Experimental investigation of the grindability and compatibility of iron ore particles

摘要

Iron ore is a major mineral resource and mining is a primary industry and a major contributor to Australian economy. In the iron ore industry, the size of iron ore products are required to be within the proper range for better handling, transportation and storage. Grinding and compaction are widely used for size reduction and aggregation of raw iron ore. Both processes are capital- and energy-intensive. Therefore, it is important that the grinding and compaction process are properly designed and operated at optimum operating conditions.Grinding is a common process to reduce particle size. Improving grinding energy efficiency, however, represents a significant challenging problem in research community for years. The phenomena involved in grinding are very complicated and multi-scaled. Correspondingly, the control and optimisation of a grinding process is better developed at the particle scale. The grinding performance of a grinding circuit depends on the grinding environment as well as and the 'grindability' ofthe feed particles. To test the grindability of particles, two types of experiments can be conducted. One is to test the bulk grindability of particles (e.g. the Bond index). Another is to investigate the breakage behaviour of individual particles. The single or individual particle approach can overcome this problem by generating information that can be generally used for the evaluation of the breakage behaviour of particles under a given condition.Compaction is an economical and efficient processing method to transform loose powders into a dense compact. Density and mechanical strength are two main characteristics of the product and they change during the compaction process. The performance of compaction is affected by compaction condition and properties of particles, including compaction load, particle size, mixture, moisture and lubricant. Better understanding of these effects can help optimise the compaction process.Therefore, this work aims to investigate the breakage and compaction behaviour of iron ore particles under different conditions. The impact test will be performed to exan1ine the breakage of individual iron ore particles, and the die compaction and unconfined compression will be carried out to examine the density and mechanical strength of formed compacts.