Geostatistical analysis and simulation of a metallurgical parameter towards improved mining efficiency and confidence in the geological model of a kimberlite

The construction of geological models of kimberlites during an evaluation project typically suffers due to a lack of outcrop and dependency on visual core-logging criteria. A case study is presented showing how the inclusion of a metallurgical parameter (% Dense Media Separator, or DMS yield) obtained from large diameter drilling can be used to: • enhance geological definition in a kimberlite, • corroborate and support the identification of geological units, and • contribute towards understanding the volcanology at the time of emplacement. DMS yield represents the ratio of the mass of wet concentrate/mass of wet head-feed to the sampling plant and is a relative value. The %DMS yield data exhibited spatial structure within the three lobes which allowed the construction of variograms for unit M/PK, the dominant kimberlite type in the South lobe of the AK06 kimberlite. This kimberlite type revealed an extreme range of %DMS yield values which will present a challenge to the recovery of diamonds. It was therefore essential for mine planning purposes that zones of high %DMS yield were accurately defined and quantified. Ordinary Kriging was applied to obtain the “best linear unbiased estimate” of %DMS yield at a local block scale. Conditional simulations using the Turning Bands and Sequential Gaussian methods were generated to quantify the variance of %DMS yield and the potential uncertainty. Indicator kriging was applied to the kimberlite to obtain the probability of intersecting %DMS yields above a particular cut-off (20%) which the main treatment plant design could not accommodate. A possible reason for the high %DMS yield values in the kimberlite was proposed and the location of problematic zones illustrated in 3-D space. This study represents pro-active use of geology to investigate resource risk, delineate problem areas in advance and develop a geo-metallurgical model

Metasomatism in mantle xenoliths from the Letlhakane kimberlites: estimation of element fluxes

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Overview of diamond resources in Africa

From the discovery of diamonds in South Africa in 1866 until the end of 2013, Africa is estimated to have produced almost 3.2 Bct out of a total global production of 5.03 Bct, or 63.6% of all diamonds that have ever been mined. In 2013 African countries ranked 2nd (Botswana), 3rd (DRC), 6th (Zimbabwe), 7th (Angola), 8th (South Africa), and 9th (Namibia), in terms of carat production and 1st (Botswana), 4th (Namibia), 5th (Angola), 6th (South Africa), 7th (Zimbabwe), and 9th (DRC), in terms of value of the diamonds produced. In 2013 Africa produced 70.6 Mct out of a global total of 130.5 Mct or 54.1%, which was valued at US$8.7 billion representing 61.5$ 14.1 billion.http://www.episodes.orgam2016Geolog

Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: an assessment of De Beers mine sites in South Africa and Canada

De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average = 13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site�s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.</p

Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: An assessment of De Beers mine sites in South Africa and Canada

De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average = 13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (COe) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites