HWE has employed an extra 150 people at its Southern Middleback Ranges site in the past three months alone.

HWE SMR operations manager David Jones said the site was now the third biggest mine site for HWE Mining in Australia.

"We have now got a workforce in excess of 400 people," Mr Jones said.

"We continue the focus of local employment opportunities.

"We will open up our own (recruitment) office in Whyalla at some time in the future.

"I am just really keen to get local people."

Mr Jones said the larger workforce was to cope with an increase in overall production - of both magnetite and hematite, to fill OneSteel's export orders.

"We have had an increase in production from 1.1million bcm (bank cubic metres) to in excess of 1.3 million bcm a month," he said.

That increase has lead to additional equipment being put into production, more staff to operate them and extra positions to cover training staff.

While some of the new staff employed in recent months have moved to Whyalla to take up their positions, HWE is hoping more local people from other work environments will consider work in mining.

Among those to do so already is Katrina Daw, who was previously employed in domestic services with Whyalla Aged Care.

Three weeks ago she started work with HWE as a fatigue liaison officer.

Ms Daw initially put her name down with the view to gaining work driving mine trucks about a year ago because she was looking to do something different.

"I was looking for a change of life, change of scenery and just to follow some sort of career path," she said.

"My original application was for a dump truck driver but they felt that I had the skills to do this."

She couldn't be happier with her new job - working 12 hour day or night shifts, but with days off working the equivalent of only five months a year.

"It is so diverse," Ms Daw said of her move into the mining industry.