Potash mine waste to be backfilled

摘要

Proposed relaxation of a condition to allow backfilling of old underground workings with mining and refining effluent and the erection of a building to house plant and equipment to facilitate this, at Boulby Mine by Cleveland Potash Ltd, was approved by the North York Moors National Park Authority in February. Cleveland Potash Ltd produce potash at the mine and the process involves refining of the mined ore via a series of crushings, solutions and drying until the pure potash can be dried out whilst the remaining matter of salts, clays and minerals is disposed of out to sea with the salts and some minerals being dissolved into the sea water and the remaining solids being dispersed by sea action off shore. This method of effluent disposal has been carried out since the mine opened in the early 1970s. The most recent planning approval of 1998, which relates to the current and proposed mining operations up to 2023 (see Mineral Planning 71 p.39), provides conditions to continue this method of effluent disposal. However, in recent years there has been discussion with the applicants regarding a more long term sustainable method of effluent disposal and this proposal for backfilling of mine workings with mineral waste is a result of research and experimental work.