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Hostaflot LSB and Hostaflot M92 increases recovery rates, concentrate quality and profitability in polymetallics mine

The Bottom Line

By switching to Clariant’s reagents, one Peruvian mining operation…

  • Achieves target copper and lead recovery levels
  • Would increase zinc recoveries in low pH application
  • Improves concentrate quality
  • Increases mineral throughput of circuit
  • Reduces collector delivery lead time and required inventory levels
  • Increases copper concentrate sales revenue by up to 74% and lead concentrate revenue by up to 43%


To take advantage of favorable mineral market conditions, a multinational polymetallic mining operation in Peru sought to increase production of its crushing, grinding and flotation circuits from 3,000 tons per day to 4,200 tons per day. As a result, copper and lead concentrate recovery rates and quality suffered.

Clariant technicians worked with mine representatives to replace its current collector with a new level reagent that would increase recovery rates by up to 3% to achieve target production levels. By simultaneously increasing concentrate quality, the mine stood to gain a significant financial gain through a higher selling price.

With its current collector imported from another country, the mine wanted the new reagent to be locally sourced in Peru, so it could: a) shorten lead time of product deliveries; b) avoid missed shipments; c) lower the collector costs; and d) minimize required inventory quantities and costs.


To keep pace with demand from for its lead and copper products from customers in China, Europe and the United States, this major polymetallics mining operation increased its circuit output by 40%. Even though the mine still operated within the circuit’s designed maximum capacity of 4,200 tons/day, the increase resulted in shorter conditioning and flotation time periods, leading to high values in intermediate tailings.

The change exposed a weakness in the expensive Thionocarbamate collector the mill was using to process a galena feed that consisted of 90% sulfur. Copper and lead recovery rates plummeted to 2 to 3% below target levels and concentrate quality suffered.

In an attempt to increase recovery levels, mine engineer experimented with the Thionocarbamate collector, which cost $ per kilogram. They adjusted dosage and injection points of the collector between the grinding and flotation stages. All of the experiments failed to achieve target recovery rates at the increased production tonnages.

With its current collector failing, mine officials considered adding equipment to the circuit to improve recovery rates. Clariant offered a better solution through a different type of chemistry, which cost less than the mine’s Thionocarbamate collector and was locally sourced.


From ore samples provided by the mine, Clariant engineers conducted in-house lab experiments with much less expensive and more effective Dithiophosphate and Dithiophosphate/ Mercapto reagents. In addition to searching for the most effective reagent for lead and copper recoveries, Clariant tested for the mine’s low-pH zinc flotation circuit.

After close scrutiny of trial results, Clariant determined that Hostaflot LSB was the most effective solution for achieving target lead and copper recovery rates in this application. Hostaflot M92 was the best performer to increase Zinc recovery when the flotation circuit worked with a pH of less than 10.

The mine experimented with Hostaflot LSB at the 4,200-ton/day production rate, adding the collector in liquid form to the flotation circuit without dilution. At the same dosage rate as the mine’s previous collector, Hostaflot LSB increased copper and lead recovery rates to 58.1% and 91.3% respectively, meeting the mine’s target recovery expectations. Hostaflot M92 performed equally as well, increasing recovery of zinc to 91.5%.

Concentrate quality improved to 24.66% for copper and 59.87% for lead with Hostaflot LSB, which allowed the mine to sell these products at a higher price. If the mine chooses to use Hostaflot M92 in lower pH conditions, zinc concentrate quality would increase by approximately 1.0%.

When compared to the cost of the previous collector, the mine saved 50% by switching to Clariant’s Hostaflot LSB and Hostaflot M92.


Clariant’s Hostaflot LSB and Hostaflot M92 collectors allow the mine to process 4,200 tons/day of feed material to significantly increase mineral production. Monthly copper concentrate production now totals 840 tons, up from 540 tons, and lead concentrate totals 5,190 tons, up from 4,080 tons.

In this application, Hostaflot LSB and Hostaflot M92…

  • Improve monthly copper concentrate revenues by 74% and lead concentrate revenues by 43%
  • Increase recovery rates by 2 to 3%
  • Raise concentrate quality
  • Eliminate the costly investment in additional processing equipment
  • Cost $3.50/kg, half the price the previous collector
  • Lower collector inventory levels and cost through local sourcing
  • Shorten collector delivery lead time from weeks to 4 days


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