[1] Prominent mining engineer William Henry Corbould was invited to the field by Douglas MacGilvray, who held options over several tenements, and immediately noted similarities between the Mount Isa orebodies and those of Broken Hill, New South Wales.

Corbould secured an option over 400 acres (160 ha) and in January 1924 floated Mount Isa Mines Ltd (MIM) in Sydney with himself as director and general manager.

[1] Corbould played a key role in consolidating the ground under MIM, investing his own funds and persuading the state government to extend the railway from Duchess.

[2] The early years were characterized by the struggle to develop the lead–zinc ore bodies, including the need to finance drilling, metallurgical test work and shaft sinking, and there was significant doubt that Miles' discovery would ever amount to much.

[5] The cost of developing the Mount Isa ore body was so high that the owners had to turn to ASARCO to obtain sufficient finance to bring the operation into production.

[6] The project was running behind schedule and over budget, which ultimately resulted in ASARCO sending its own man, Julius Kruttschnitt II, to take charge.

[6] Kruttschnitt arrived in 1930 to find that bills were going unpaid because there was no money to pay them, the shafts were flooding, and the construction of the surface plants was months behind schedule.

[9] By June 1933, the debt owed by MIM to creditors around the world, £2.88 million, was equal to 15% of all income tax paid in Australia in 1932.

7 level of the Black Star lead-zinc ore body allowed the existence of an economic copper deposit to be established.

[12] MIM was still not in a position to mine the copper, because it had stockpiles of lead bullion and zinc concentrate that could not be sold due to the war.

[15] The drilling program was curtailed in 1957 due to a fall in metal prices and heavy capital expenditure in the existing operations.

[25] It also, in 1958, constructed a new dam on the Leichhardt River to supply water to Mount Isa and the MIM operations[16] and thus Lake Moondarra was created.

[7] The difficult nature of the Mount Isa ore bodies has meant that the company had always needed to be at the forefront of mining technology.

[34] Then, in the 1970s through to the 1990s, it became a world leader in developing new mining techniques and processing technologies as a response to declining metal prices and rising costs.

[41] Arising from this work, Jameson developed the idea of mixing air and concentrate slurry in a pipe, referred to as the "downcomer", that was inserted into the flotation column.

[41] Further research showed that mixing the slurry and the air in the downcomer meant that much of the height of traditional flotation columns was unnecessary and the concept of the short "Jameson Cell" was born.

[41] In 1988, MIM decided to increase the capacity of its heavy medium plant slimes flotation circuit to improve lead recovery and, following investigations of various alternatives, installed two full-scale Jameson Cells in the lead–zinc concentrator in 1989.

[41] In April 1989, MIM Holdings acquired the world rights to the metallurgical applications of the Jameson Cell, began marketing the technology and continued to develop it.

MIM investigated various existing fine grinding technologies (such as ball mills and tower mills) but found them to be uneconomic in the MIM application and also that the high consumption rate of the steel grinding medium resulted in iron contamination of the mineral surfaces, making them less susceptible to flotation recovery.

[42] The IsaMills typically use an inert grinding medium (such as ceramic balls, smelter slag or silica sand) and avoid the problem of inhibiting flotation of the fine particles with iron deposits.

[42] MIM decided to license the technology to other users in 1999,[42] and the latest information available states there are 121 IsaMills installed in concentrators around the world.

[43] After the completion of the P49 shaft at Hilton in 1975, the project there was wound down due to a decline in the world prices for lead, zinc and silver.

[15] It achieved this by removing lighter (unmineralised) rock fragments and rejecting them from the concentrator before they reached the grinding mills that were the bottleneck for the plant.

[45] Payments by smelters to mining companies are lower for bulk concentrate due to the higher cost of running processes that can treat them.

Silver and zinc were removed from the surface oxidized zone and were deposited as supergene ore at a depth above the primary ore.[59] Copper occurs in brecciated "silica-dolomite" rock.

The Mount Isa Mines Panel Assessment Study recently spent 4 years investigating the air quality and the effects on community health.

Mount Isa Mines is currently the highest atmospheric emitter of sulphur dioxide, lead and several other metals in Australia.

Queensland Health reported in 2008 that the average blood lead concentration for children (1–4 years old) in Mount Isa was five microgram/dL and 11.3% exceeded 10 microgram/dL.

Recent medical research has documented adverse health effects at blood lead concentrations above five microgram/dL and possibly down to as low as two microgram/dL.

[60][61][62][63] In September 2014 Sharlene Body won the rights to a civil trial against Xstrata for allegedly causing neurological damages to her son via neurotoxic emissions of lead.