Currently the chrysotile mines are harnessing chrysotile from chrysotile dumps, and there are efforts by government to resume full-scale mining of chrysotile, making Zimbabwe the only country in Africa to still be producing and using chrysotile asbestos. In Africa, major producers of asbestos were South Africa, Swaziland, and Zimbabwe ...
The nature and occurrence of mineralisation in the early Precambrian crust of Zimbabwe. Developments in Precambrian Geology, 8, 555-591.
The Zvishavane Ultramafic Complex (ZUC) is a metamorphosed ultramafic-mafic body exposed within the Zvishavane gneiss complex in south central Zimbabwe. The complex hosts Africa's largest mine and reserves of …
worked in buildings with chrysotile asbestos [8]. Zimbabwe has two major factories that manufacture chrysotile asbestos products, and which have been the main users of chrysotile asbestos since their establishment in the 1940s and 1950s. A limited number of papers have reported temporal trends in personal exposure
Chrysotile is a mineral, not a rock. Another name for this mineral is "white asbestos." In fact, chrysotile asbestos is the most commonly used asbestos mineral. ... Zimbabwe. Onto the crucial buyers' question: how much do chrysotile gemstones cost? ...
Chrysotile, the most commonly used asbestos mineral, has been mined extensively in Russia, Canada, China, Zimbabwe and South Africa. Where Does Chrysotile Occur? Chrysotile is one member of a family of sheet silicates called serpentine. ... Although the …
Electron microprobe analyses were performed on chromites from Mashava Igneous Complex (MIC), a Neoarchean ultramafic complex located in the western extremity of the …
Although neither oxygen nor hydrogen isotope studies have yet been conducted on chrysotile asbestos deposits in southern Africa, H and O isotope studies from elsewhere suggest that tremolite and chrysotile are formed from tectonically controlled magmatic and meteoric hydrothermal systems with formation temperatures of tremolite (∼360°C ...
AsbestosAsbestos is a fibrous natural material that possesses outstanding technological properties exploited since the time of its discovery for the manufacture of various building materials.
PDF | On Nov 1, 2023, Jeff B. Chaumba and others published Geochemistry of extremely modified chromites from the chrysotile asbestos-bearing Zvishavane Ultramafic Complex, south central Zimbabwe ...
ZUC hosts the largest deposit of chrysotile asbestos in Africa. ... The Zimbabwe Ultramafic Complex was metamorphosed at relatively high temperatures (542-779°C) and low pressures (1.2-2kbars ...
Figure 1: Chrysotile serpentine rock 1. Preamble The Government of Zimbabwe has successfully managed to deal with chrysotile asbestos by forming a multi-sectoral body, representing Government, Labour and Industry. The Zimbabwe National Chrysotile Taskforce (ZNCTF) gives technical advice and guidance regarding the topical issue of chrysotile ...
Waste rock dumps (WRDs) had more (p<0.05) sulphur (2.7-3.3%) than the control (0.8±0.03%). ... This difference, together with the fact that Zimbabwe chrysotile has 2 to 3 orders of magnitude less ...
In Zimbabwe, exposure to chrysotile asbestos has been ongoing for many decades since the mines were opened around 1910 and manufacturing began around 1943 [8]. In occupational exposure assessment ...
The Zvishavane Ultramafic Complex (ZUC) in the south central part of the Zimbabwe craton is comprised of coarse-grained serpentinites, metadunites and metagabbros and hosts Africa's reserves, and...
The Mashaba Asbestos Mine is located in Masvingo, Zimbabwe. This mine primarily extracts chrysotile, a type of asbestos. The geological composition of the surrounding area is predominantly serpentinite, which serves as the host rock for the ore deposits.
rock wool fibers. Our study suggests that both chrysotile and rock wool fibers could induce chromosome aberrations and DNA damage. These materials are worthy of further study. Keywords Chrysotile .Rockwoolfibers .Mutagenicity . Singlecellgelelectrophoresis .Micronucleustest Introduction Asbestos is an abundant, inexpensive, and geographically
The Mashava Igneous Complex (MIC) (e.g., Wilson, 1968a, b) is host to the second most important chrysotile asbestos occurrence in Zimbabwe after the Zvishavane Ultramafic Complex (e.g., Laubscher ...
pacity (Laubscher, 1986). Mining of chrysotile asbestos in Zimbabwe (at Shabani mine), however, ceased in 2013 (U.S. Mineral Commodity Summaries, 2020). Mining of chrysotile asbestos from the ...
THE NATURE AND OCCURRENCE PRECAMBRIAN CRUST OF ZIMBABWE J.F.WILSON AND T.H.C.NUTT ABSTRACT A review of the early OF MINERALISATION IN THE EARLY Precambrian geological record (approximately 3500 - 2500 Ma) of Zimbabwe shows that the distribution of mineralisation pertaining to gold, nickel, chromite, chrysotile asbestos and …
A clear dose-response between asbestos exposure and functional loss has been demonstrated, with mean losses from predicted of about 400-600 cc in vital capacity in the 10% of the population with heaviest exposures. As part of the effort to establish industrial practice and public policy regarding asbestos in Zimbabwe, we have conducted a cross-sectional study of the chrysotile …
As part of the effort to establish industrial practice and public policy regarding asbestos in Zimbabwe, we have conducted a cross-sectional study of the chrysotile mines and mills. A stratified random sample of workers with greater than 10 years of exposure has been evaluated by spirometry, chest r …
In the present work, chrysotile asbestos from various localities around the world has been collected and investigated by 57 Fe Möss and FT-IR spectroscopies as well as FE-SEM and EDS. The aim of this work was to obtain more data about the oxidation state of iron in chrysotiles and the dependence of Fe 2+ /Fe 3+ ratio on the origin of chrysotile. . …
The Government of Zimbabwe has endorsed the Zimbabwe Chrysotile Position Paper which represents national policy on mining, value-addition, trading, use and handling of chrysotile …
Chrysotile and the other varieties of asbestos are found in practically every country in the world, but generally not in quantities or quality that allow commercial exploitation. ... Zimbabwe: 170 000: Other: 50 000: Total: 2 080 000: Sources: Natural Resources Canada, U.S. Geological Survey, The Chrysotile Institute: World consumption ...
The Zvishavane Ultramafic Complex (ZUC) is a metamorphosed ultramafic-mafic body exposed within the Zvishavane gneiss complex in south central Zimbabwe. The complex hosts Africa's largest mine and ...
Chrysotile, the most commonly used asbestos mineral, has been mined extensively in Russia, Canada, China, Zimbabwe and South Africa. Where Does Chrysotile Occur? Chrysotile is one …
The Mashaba Asbestos Mine is located in Masvingo, Zimbabwe. This mine primarily extracts chrysotile, a type of asbestos. The geological composition of the surrounding area is …
The Zvishavane Ultramafic Complex (ZUC) is a metamorphosed ultramafic-mafic body exposed within the Zvishavane gneiss complex in south central Zimbabwe. The complex hosts Africa's largest mine and reserves of high-grade chrysotile asbestos. Rock types of the ZUC range from serpentinites, metadunites, and metagabbros.
thus, this is the first one of its kind in a Zimbabwe workplace setting. A JEM specific for chrysotile asbestos in ACM industries in Zimbabwe will be useful in future epidemiology studies rather than using or extrapolating exposure estimates from international studies which may not be suitable for Zimbabwe workplaces settings. Hence, this ...
Electron microprobe analyses were performed on chromites from Mashava Igneous Complex (MIC), a Neoarchean ultramafic complex located in the western extremity of the Masvingo greenstone belt (MGSB) in Zimbabwe. In backscattered electron images (BSEs), the massive, layered, and sometimes serpentinite hosted chromite crystals are rimmed by a thin …
According to the results, chrysotile and rock wool fibers caused micronuclei to form in a dose-dependent manner in V79 cells; olive tail moment values increased in a dose- and time-dependent manner. When V79 cells were exposed to a concentration of 200 μg/ml, the degree of DNA damage induced by chrysotile fibers was greater than rock wool fibers.
Chrysotile in Serpentine (Chrysotile in Serpentine). Chrysotile in Serpentine is a fibrous form of serpentine. This material is commonly used for jewelry and accessories. Also called white asbestos, the gems made from this material should be treated with safety, as asbestos is classified as an agent that can cause cancer. It is often used in manufacturing, including the …
The MIC chromitite deposits have received even lesser attention than those occurring at Shurugwi, and thus, are the focus of this investigation. ACCEPTED MANUSCRIPT 3 The MIC is host to the second most important chrysotile asbestos occurrence in Zimbabwe after the Zvishavane ultramafic complex (e.g., Laubscher, 1968; Wilson, 1968a, b).
The predominant mineral extracted from this mine is chrysotile, a type of asbestos, with the principal waste material being talc. The geological setting of the mine is characterized by the presence of dunite, a type of ultramafic rock, as the host rock in the surrounding area.
One was from Zimbabwe (Chrysotile A) and the other was a composite sample of fibres from Canadian mines in the eastern townships of Quebec (Chrysotile B). ... As a result, chrysotile originating from serpentine rock is often found in air and water due to natural weathering (Nicholson & Pundsack, 1973; Neuberger et al., 1996). Workable deposits ...
routes of cracks by vein chrysotile. Talc and magnetite are prevailing impurities in many chrysotile deposits, and the magnetite may appear as banded margins to the fibre veins or be disseminated throughout both the wall rock and the fibre. Asbestos Chrysotile Fibrous Amphiboles (White Asbestos) 3MgO, 2SiO2, 2H20 Amosite Anthophyllite Crocidolite
These include the serpentine mineral chrysotile (also known as 'white asbestos'), and the five amphibole minerals ... and are found in many areas where the original rock mass has undergone metamorphism ... incidences: chrysotile A, 44%;chrysotile B (from Zimbabwe), 53%; crocidolite, 42%; amosite, 27%; anthophyllite, 16%. Further results are ...
Data on the health effects caused by locally mined chrysotile asbestos in Zimbabwe have been very limited. The prevailing local view has been that risk is minimal. In this report we critically reassess the cases of 51 individuals with asbestos exposure who have been compensated by the Central Pneumoconiosis Bureau since independence in 1980. Results …