Complex sentence: From the mid- 1980s until its closure, New Cheshire was the only salt works in the UK still to use the natural brine pumping method, as well as the only British company to supply salt for pharmaceutical use.
Split into simpler sentences: From the mid- 1980s until its closure, New Cheshire was the only salt works in the UK still to use the natural brine pumping method. It was also the only British company to supply salt for pharmaceutical use.