The Turkish mining company Mikroman, which has been mining and processing quartz since 1991, set itself the targets of improving product quality and increasing capacity at its three processing plants in Turkey. They have been able to achieve these goals, as well as other gains, by installing four TOMRA high-capacity sensor-based sorting systems.
In addition to being the most efficient way to sort particles, sorting machines deliver a wide range of commercial advantages to industrial mineral sorting businesses. These include a decrease in mining and haulage costs, reductions in energy consumption and water consumption, improvements in quality and productivity, and increases in recovery. Sensor-based sorters also make it possible to significantly increase the lifetime of a mining operation.
In the case of the Mikroman Company, quartz rocks are blasted and crushed at open-pit mines. For crushing, washing and sorting the raw materials, the company runs its own mineral processing plants. During 2018 two of the company’s three plants, in Muğla and Aydin Provinces, each installed a TOMRA PRO Secondary LASER sorting machine. The third plant, in Usak Province, invested in a LASER sorter plus a COLOR sorter.
TOMRA’s Area Sales Manager, Jens-Michael Bergmann, explained: “TOMRA’s COLOR sorting machines employ a high-resolution camera, which recognizes materials based on their color. Rocks with visible contamination are detected and sorted out, resulting in better recovery rates and higher quality than is possible with manual sorting."
"Our unique multi-channel LASER sorter delivers even more benefits for Mikroman to achieve the highest purity levels and maximize profits. The scattering effect of multiple laser beams distinguishes a rock containing quartz from its identically colored neighbour. Under the laser beam a pure or non-contaminated quartz rock registers as a glow crystal, whereas similar-looking rocks with no quartz content remain dark, without any visible scattering,” says Bergmann.
Mikroman combined these two technologies for the best results and recovery.
MINERALS SORTED BY COLOR, COMPOSITION AND SIZE
Of all three Mikroman Mining Company processing plants, the one in Usak Province demands the most precise mineral sorting. Before sorting, the feed material is screened by size: The 40-100mm stones are treated with a higher priority; stones measuring 20-40mm in size are sent down the sorting line in a separate batch. Here, the combination of a TOMRA COLOR sorter and TOMRA LASER sorter is used to differentiate products according to four predetermined qualities. These are:
- white and light grey quartz, with low iron oxide content, for use as artificial stones (A);
- grey and yellow quartz, for use by the glass industry (B);
- colored quartz, for ferrosilicon used by the metallurgical sector (C);
- and colored gravel (D), also for ferrosilicon, currently goes with the waste.
After crushing and washing (through a trommel screen), Mikroman’s sorting process consists of four key steps. In the first step, minerals are screened by size, with only stones measuring 40-100mm going through to the next stage. In the second step, the LASER machine sorts out the waste and colored gravel from the quartz pieces at about 70 tph capacity. In the third stage, the remaining minerals are sorted into two streams, one for colored quartz, the other for the white and light grey quartz and the grey and yellow quartz. Finally, these two streams are hand-sorted into product types, with some further removal of remaining gravel and waste.
These precise distinctions, resulting in higher product quality, were not possible before the acquisition of the TOMRA machines.
TOMRA’s Service team worked on-site with Mikroman, as it does with all customers, to optimize the performance of the machines.
Nazmi Çetin, Mine and plant Manager at Mikroman, commented: “Before having TOMRA sorters, we were worried about quality and low capacity. But now we have achieved the desired quality standard and we have seen a decrease in waste, which means productivity has increased. The system design is quite successful and the TOMRA service team is good at their job.”
In addition to industrial mineral sorting, TOMRA’s technologies also effectively sort diamonds, all kinds of metals ores, slag metals and coal. Find out more about TOMRA Mining's COLOR and LASER sorting machines.