The red syenite of the Pilansberg complex as a nepheline source for the South African ceramics and glass industry

Abstract

A viability study was undertaken on a farm Zandrivierspoort 210 JP, in the Pilanesberg Alkaline Complex to investigate the red syenite deposit. The red syenite deposit of interest is located in the south-western quadrant of the Pilanesberg. It is a potential source of nepheline, which is used as a flux in glass and ceramics industry. The study was aimed at establishing the demand for the material in South Africa and the market logistics related to its exploitation. Glass and ceramics manufacturers have different specifications as far as the quality and the product form is concerned. A market study conducted indicated that glass manufacturers require already beneficiated material with a low Fe content, depending on the kind of glass being manufactured. Ceramics manufactures also want material with low Fe content, but the material can be unbeneficiated as most of these factories already have facilities to remove Fe and other gangue. The common requirement is that material must be crushed and milled to a specific size. Red Syenite complies with the specifications of the ceramics manufacturer and did not comply directly with the specification of the glass manufacturer. The main reason for not non-compliance with glass specifications can be attributed to the fact that the material supplied was unbeneficiated. A major concern from the industry is the continuity of production from the deposit and an assurance of constant quality. It was also established that the availability of substitutes such as feldspar at a lower cost than nepheline results in an unwillingness of potential users to source nepheline despite its advantages. It is recommended that extensive geological studies be undertaken to confirm the resources and reserves of the entire nepheline-bearing deposits in the Pilanesberg. The mining of the deposit will be undertaken by employing a quarrying method, which will be followed by opencast to a depth of 50m. The Run-Of-Mine (ROM) will be crushed and milled to sizes specified by clients and the beneficiation process will follow. A financial investigation based on the known facts about the deposit established that capital, production rate, and selling price have the highest influence on the viability of the project. Transport and operating costs in this case showed a less significant influence on the viability of the project.