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Diamond weighing 222 carats - new extraction technologies of AGD

27 may 2019

In the end of May, AGD Diamonds will hold an auction for the sale of special diamonds weighing +10.8 carats on the e-trading platform of its Belgian trading arm, Grib Diamonds in Antwerp. A feature of the company’s May auction will be pilot sales of large colorless diamonds of top quality (very well preserved, without technological damage - cracks and chips - during processing), which were mined at the Grib diamond pipe using new extraction technologies. One of the very large diamonds offered for sale is a stone weighing 66.95 carats.

expert_24052019_x_1.png                              Single-crystal diamond weighing 66.95 carats

Since the end of 2018, the operator developing the Grib diamond field in the north-western part of European Russia, which is AGD Diamonds, has been using new XRT technology (manufactured by TOMRA Sorting Solutions) to dress kimberlites. This method of diamond extraction is recognized by AGD Diamonds as successful and cost-effective. The use of modern technology, which is applied at diamond-mining operations in Russia for the first time, allowed AGD Diamonds to extract more than 25 diamonds of gem, industrial and near-industrial quality in 2018-2019 ranging from 40 to 500 carats in size, including very large gem-quality stones weighing more than 100 carats of top characteristics in color and quality.

                             Single-crystal diamond weighing 222.09 carats

Using the XRT technology, AGD Diamonds extracted two large excellent gem-quality diamonds weighing 222.06 carats and 127.34 carats in May 2019.

                            Single-crystal diamond weighing 127.34 carats

The program of introducing technologies for the preservation of large diamonds will be further improved. In the future, the processing plant at the Grib diamond field will function according to a new improved pattern. After refining the technological pattern of ore dressing in 2019 and launching special “intelligent” roller crushers produced by ThyssenKrupp at the dense-media separation unit, AGD Diamonds will change the settings in the ore dressing equipment and in the configuration of concentrates treatment, which will make it possible to extract gem-quality diamonds weighing up to 500 carats starting from 2020, including large fancy stones of aquamarine and yellow colors.

The applied advanced engineering solutions, including the operation of the XRT separator in combination with the non-explosive method of ore breaking by way of layer-by-layer circular milling and correct preparation of the charge mixture (its composition and piece size) to be fed to the processing plant, will finally result in low damage of stones weighing more than 50 carats.

This technology permits the factory to process (without loss of finished products, including small-size rough) a large amount of loose poor-grade ores from the crater part of the deposit extracted by simple excavation without destroying diamonds. The crater ores have one distinctive feature - despite their low diamond grade they may occasionally yield large top-quality colorless diamonds. The inclusion of tuffite ores in the dressing process using the XRT technologies and gentle disintegration of kimberlites, will allow AGD Diamonds to increase output of large-size colored stones.

AGD Diamonds' strategy is focused on a substantial increase in the production of large and very large single-crystal diamonds. As the presence of synthetic diamonds in the consumer market is growing, the company predicts a decrease in prices in the segment of small-size diamonds accompanied by a rise in prices for the unique product - large natural diamonds. In this regard, the investment program of AGD Diamonds is aimed at minimizing the destruction of diamonds in the process of ore dressing and their recovery by way of introducing the most advanced diamond extraction technologies.

Vladimir Malakhov, Rough&Polished