PROJECT DESCRIPTION
BACKGROUND
The project was implemented at CPL's Boulby Potash Mine in the Northeast Region of the UK. At the time of the inception of the project the mine discharged 8 million cubic metres of saline effluent containing cadmium and mercury into the North sea every year. The future sustainability of the Boulby mine, a major employer in the region, was dependent on the identification of alternative, cost effective waste disposal options that would significantly reduce existing environmental impacts. The metal containing faction of the waste is fine grained clay material, which is highly thixotropic with high water retention capabilities. These properties make it unsuitable for management by standard process waste handling and disposal technologies.
OBJECTIVES
The aim of the project was to undertake full scale demonstration trials to allow evaluation of waste processing and disposal techniques at a site-scale and refinement of process design. The process would represent a major operational change to a zero-discharge waste management system that would significantly reduce the volume of residual waste discharged to the North Sea. The project consisted of three main phases of activity: 1. laboratory analysis and testing; 2. pilot scale test programme; 3. large scale demonstration programme at Boulby Mine in the UK. The main component of the project was to be a Demonstration Programme utilising a specially designed and developed prototype plant to turn the existing waste into a product suitable for underground disposal via a gravity-feed system, designed and installed to provide optimum control over waste properties during transportation. The Demonstration Programme would be preceded by pilot testing which was required to allow final specification of the prototype plant and demonstration test procedures. The project would provide a unique opportunity to evaluate the potential for large-scale underground combined-waste disposal. Extensive research and testing had been undertaken in relation to the waste produced at Boulby Mine. It was therefore proposed that, following a phase of final confirmatory testing, the works to be undertaken at the mine would consist of the Pilot Programme followed by a three year demonstration Programme. The Pilot Test Programme would focus specifically on developing a process technology to allow control of waste mixtures, and gravity transportation systems that would facilitate low-cost underground disposal.
RESULTS
The project has demonstrated the viability of the disposal of waste from this mine back into the mine workings, and has investigated the technical constraints that apply to the technology. The project was nevertheless faced with a number of delays which meant that the operational test of the underground components of the demonstration plant had been running for less than one month by the time the final report was submitted. However, the report claims that the whole system is now running successfully. The result of this work gives mining companies an additional, environmentally friendly, option in the disposal of their waste. Information regarding the successful conclusion of the pilot trials has been disseminated to industrial and public sector representatives and organisations throughout the UK and other Member States, through presentation at international conferences and publications in internationally distributed technical journals. In addition, considerable public interest is evidenced by the press cuttings from the local media, i.e. Yorkshire Post, the Whitby Gazette and the Northern Echo, dating from February 2002. The web page www.clevelandpotash.co.uk/waste.htm describes the project in layman’s terms and credits the LIFE ENVIRONMENT programme. There is no dedicated project website. Work is now focused on wider public dissemination of information relating to the project and in particular the environmental benefits associated with full-scale implementation of the project and the role of the LIFE programme.The project has demonstrated the viability of the disposal of waste from this mine back into the mine workings, and has investigated the technical constraints that apply to the technology. The project was nevertheless faced with a number of delays which meant that the operational test of the underground components of the demonstration plant had been running for less than one month by the time the final report was submitted. However, the report claims that the whole system is now running successfully. The result of this work gives mining companies an additional, environmentally friendly, option in the disposal of their waste. Information regarding the successful conclusion of the pilot trials has been disseminated to industrial and public sector representatives and organisations throughout the UK and other Member States, through presentation at international conferences and publications in internationally distributed technical journals. In addition, considerable public interest is evidenced by the press cuttings from the local media, i.e. Yorkshire Post, the Whitby Gazette and the Northern Echo, dating from February 2002. The web page www.clevelandpotash.co.uk/waste.htm describes the project in layman’s terms and credits the LIFE ENVIRONMENT programme. There is no dedicated project website. Work is now focused on wider public dissemination of information relating to the project and in particular the environmental benefits associated with full-scale implementation of the project and the role of the LIFE programme.
