ASX-listed premium potassium mineral fertiliser hopeful Trigg Mining is edging closer to finalising a scoping study on the proposed development of its high-grade Lake Throssell sulphate of potash project about 170km north-east of Laverton in Western Australia. The Perth-based company, which recently tabled a maiden indicated resource estimate for Lake Throssell, says it aims to wrap up the study by the end of next month.