PhosCo (ASX:PHO) said first pass metallurgical test work results for the KM prospect within its Gasaat phosphate project in Tunisia show that a simple, single-stage flotation circuit produces commercial grade phosphate of up to 31.4% phosphorus pentoxide, according to a Tuesday Australian bourse filing.

The company said the results mean three silica flotation steps can be eliminated, reducing technical risk, process complexity, and capital and operating costs.

The company said saline Gasaat bore water can be used with minimal or zero cleaning, while concentrate grade is correlated to reagent dosage, opening the possibility of customizing reagent application to match concentrate specifications.

The company's shares rose 1% in recent Tuesday trade.