Enhancing Flotation Efficiency at NMMC’s Hydrometallurgical Plant No. 3: Innovations and Impacts

By Metals Minerals Publication Last updated Aug 18, 2025

The Navoi Mining and Metallurgical Company (NMMC), the world’s fourth-largest gold producer and Central Asia’s largest gold miner, has achieved significant advancements in flotation efficiency at its Hydrometallurgical Plant No. 3 (HMP-3). Located in Uzbekistan’s Navoi region, HMP-3 processes ore from the Kokpatas, Dovgiztau, and Auminzo-Amantoy deposits, leveraging 67 flotation machines operating continuously to enhance gold recovery. Recent innovations, including water softening with calcined and caustic soda and the addition of a new flotation machine in September 2024, have boosted gold recovery to 88% and increased ore processing capacity by 8–10%. This article explores these process improvements, their technical and economic impacts, and their role in strengthening NMMC’s position in the global mining industry, drawing from web sources and operational updates.

Flotation Process Enhancements at HMP-3

1. Advanced Water Softening Techniques

One of the key improvements at HMP-3 is the use of calcined and caustic soda to soften water used in the flotation process. Hard water, containing high levels of calcium and magnesium, can reduce the effectiveness of flotation reagents, lowering mineral recovery rates. By implementing water softening:

Improved Reagent Efficiency: Softened water enhances the performance of flotation reagents, allowing better separation of gold-bearing minerals from waste rock.
Increased Gold Recovery: This innovation has raised overall gold recovery at HMP-3 to 88%, a significant leap from previous rates, aligning with NMMC’s goal of maximizing ore value.
Environmental Benefits: Softer water reduces scaling in equipment, extending machinery life and minimizing maintenance downtime, contributing to sustainable operations.

2. Addition of a New Flotation Machine

In September 2024, NMMC installed an additional flotation machine at HMP-3, bringing the total to 67 units. This expansion has had a measurable impact:

Capacity Increase: The new machine boosted ore processing capacity by 8–10%, from 8 million tonnes per year to approximately 9 million tonnes, with plans to reach 10 million tonnes by the end of 2025.
Operational Efficiency: The additional machine, manufactured locally at NMMC’s Navoi Machine-Building Plant, supports Uzbekistan’s industrial self-reliance while ensuring timely project execution.
Scalability: Coupled with plans to expand flotation, bio-oxidation, filtration, drying, and roasting workshops, this upgrade positions HMP-3 to handle growing ore volumes from Kokpatas, Dovgiztau, and Auminzo-Amantoy.

3. Technical Solutions for Processing Quality

NMMC’s flotation specialists are introducing innovative technical solutions to further enhance processing quality:

Reagent Optimization: Fine-tuning reagent dosages and introducing advanced flotation chemicals improve the selectivity of gold recovery, minimizing losses in tailings.
Automation and Monitoring: Digital systems monitor flotation parameters in real-time, ensuring consistent performance and enabling rapid adjustments to process conditions.
Inter-Cycle Flotation: Since 2010, HMP-3 has implemented inter-cycle flotation schemes, increasing metal recovery in flotation concentrate from 72% to 82%, as reported on NMMC’s official website.

These advancements build on NMMC’s history of innovation, including the 2017 introduction of oxygen-lime oxidation at HMP-5 and the 2019 WIPO Gold Medal-winning technology for extracting gold from refractory sulfide ores at HMP-3.

Economic and Operational Impacts

The flotation improvements at HMP-3 have significant implications for NMMC’s operations and Uzbekistan’s economy:

Increased Gold Output: The 88% gold recovery rate enhances production from Kokpatas, Dovgiztau, and Auminzo-Amantoy, contributing to NMMC’s 2024 output of 3.1 million ounces and $7.4 billion in revenue.
Cost Efficiency: Locally manufactured equipment, like the new flotation machine, saved $56 million in foreign currency, aligning with NMMC’s commitment to supporting local industries.
Capacity Expansion: The 8–10% capacity increase supports NMMC’s $1 billion 2024 investment program, with $363.5 million already allocated to projects like HMP-3’s seventh mill, costing $281.1 million.
Global Competitiveness: Higher recovery rates and expanded capacity strengthen NMMC’s position as the world’s fourth-largest gold producer, with a 148 million-ounce resource base, including the 101 million-ounce Muruntau mine.

Alignment with Global and Regional Trends

The enhancements at HMP-3 resonate with global mining trends and regional economic goals:

Technological Innovation: NMMC’s adoption of automation and advanced reagents mirrors global advancements, such as drone-based surveying and IoT safety systems in India’s Jabalpur gold project.
Sustainability: Water softening and equipment localization reduce environmental and economic costs, aligning with sustainable mining practices seen in Ivory Coast’s Tongon mine.
Economic Resilience: By maximizing gold recovery, NMMC supports Uzbekistan’s economy, similar to India’s Atmanirbhar Bharat initiative leveraging Jabalpur’s ₹1.5 lakh crore gold reserves to reduce import dependency.

Challenges and Opportunities

Challenges

Ore Complexity: The refractory sulfide ores from Kokpatas and Dovgiztau require advanced processing, increasing operational complexity and costs.
Investment Needs: Sustaining HMP-3’s upgrades demands significant capital, with $1 billion allocated for 11 projects in 2024, posing fiscal challenges.
Environmental Compliance: Enhanced flotation must meet strict environmental standards to avoid regional backlash, a concern in global mining operations.
Skilled Workforce: Implementing technical solutions requires ongoing training, as seen with HMP-5’s 2,500-person township for skilled workers.

Opportunities

Further Recovery Gains: Continued innovation could push recovery rates beyond 88%, unlocking additional value from NMMC’s 148 million-ounce resource base.
Local Manufacturing: Expanding production at the Navoi Machine-Building Plant, as seen with the flotation machine, supports Uzbekistan’s industrial growth.
Global Leadership: Enhanced efficiency positions NMMC to compete with global giants like Barrick Gold, which is divesting assets like Tongon to focus on copper.
Job Creation: Upgrades at HMP-3, like HMP-7’s 1,000 new jobs, can drive employment, mirroring India’s projected 10,000–15,000 jobs from Jabalpur’s gold mine.