Developing a greener mining industry has been a top priority worldwide in recent years, including in China. Molybdenum miner Luanchuan Hengyu Mining Co Ltd (Hengyu Mining) was established in 2006 and currently mines about 1.45 Mt/y of rock from open pit mining. It also produces sand and gravel aggregate from the waste. Hengyu Mining has a proven molybdenum metal reserve of 76,300 t. The ore is a porphyry, with molybdenite and pyrite as the main metallic minerals and feldspar and quartz as the non-metallics.
Since its establishment in Luoyang, Henan Province, Hengyu Mining has adhered to the environmental protection principle that “clear waters and green mountains are as valuable as gold and silver mountains.” In practice this includes an awareness that an environmentally friendly mine need to not only include land reclamation and afforestation but also comprehensive resource utilisation, reduction in energy use, and environmental protection.
Hengyu Mining has also been actively seeking advanced technology for more efficient development of its mineral resources – exploring solutions that will improve its production process. In 2021, after inspection and design by HPY Sorting Technology’s team of experts, Hengyu Mining changed its original ore sorting method by adding HPY Sorting Technology’s XRT-based intelligent ore sorting equipment for the pre-rejection process. HPY is based in in Ganzhou, Jiangxi, and is one of China’s leading suppliers of ore sorting technology.
The molybdenum ore is penetrated by X-rays, imaged by machine vision, and judged by artificial intelligence to help identify what is considered useable ore and waste rock. Once the machine has identified useable ore and waste rock, they are sorted with high-pressure compressed air that sorts the ore and waste rock into two separate belts that carry each sorted material to the next step in the beneficiation process.
Investing around $1.45 million, Hengyu Mining constructed an intelligent ore sorting plant consisting of four sensor-based ore sorting machines, using HPY Sorting Technology’s The Circle Series (model C1500) for pre-selecting molybdenum ore and rejecting waste rock.
“The original design capacity of our plant was 5,000 t/d. After the technical modification with four HPY The Circle Series units, the processing capacity was increased to about 8,000 t/d. Our raw ore grade is relatively low – about 0.05% when it enters the sorting machine. After processing through the HPY The Circle Series, the concentrate grade improves by an average of 0.03% to 0.08%. The recovery rate has also increased to 85%,” according to Mr Feng, the Production Technical Supervisor of Hengyu Mining.
HPY’s intelligent ore sorting technology allows Hengyu Mining to reject waste rock in advance without using water or other methods. By using sensor-based ore sorting machines early in the beneficiation process, it helps reduce the consumption of water, electricity, and materials downstream, while also lowering production costs, producing less solid waste, and improving economic efficiency. Moreover, waste rock can be utilised to produce sand and gravel aggregate. With the intelligent ore sorting process, Hengyu Mining has dramatically increased its mineral resource utilisation rate and reduced its greenhouse gas emissions. It is currently in the process of seeking recognition as a ‘National Green Mine.’
Annual economic benefits of approximately $6.33 million are achieved by using HPY Sorting Technology’s intelligent ore sorting equipment. The production capacity has increased from 5,000 t/d to 8,000 t/d (consisting of 5,000 t of ore for further ball mill processing and 3,000 t of waste rock that will be mainly utilised as sand and gravel aggregate). Four sets of The Circle Series ore intelligent sorting equipment can provide a maximum annual output of 900,000 t of waste rock. Early rejection of waste rock results in 280 t more molybdenum metal produced annually, saving 18,000,000 kWh of electricity worth $2.1 million.
The Circle Series HPY Sorting Technology says is the world’s first ring-shaped structured intelligent ore sorting machine. With a unique circle structure, The Circle Series features a super large processing capacity (up to 300 th) and an ultra-small size, with the models ranging from 14.8-32 m2, and a processing grain size of 5 to 90 mm.
Using advanced intelligent XRT sorting technology and aerial imaging technology, the image quality of the machine HPY says is improved by 30% compared to previous generations of ore sorting machines. The AI calculation capacity has been increased by 400%, processing over 10,000 ore particles per second.
The separation system uses high-speed multi-row air jets with a single nozzle diameter of 2 mm. The AI algorithm can intelligently manage the jet air stream based on the grain size of the ore, so even a 5 mm particle can be hit accurately. The machine also features the HPY Cloud Platform: with an intelligent online cloud monitoring system, the operator can monitor the operation status from anywhere in real time. The Circle Series is also easy to maintain due to its unique circle structure.
