Characterisation of particulate matter emissions from the Zimbabwe Mining and Smelting Company (ZIMASCO) Kwekwe Division (Zimbabwe): a ferrochrome smelter

Particulate matter emissions from stack number 2 of a majorferrochrome smelter, Zimbabwe Mining and Smelting Company(ZIMASCO) were characterized and the rates at which the elementsCr, Fe, Cu and Zn and total ferrochrome dust are emitted into theatmosphere were determined. The extent of soil contamination bythe dust deposited around the smelter in the generally prevailingsoutheasterly wind direction around the smelter was carried out.The highest concentrations of Cr and Fe occurred in the fineparticulates of sizes less than 59 m whilst that of Cu and Znoccurred in the coarse particulates of size range 70-100 m.The emission rates from stack 2 were; total ferrochromeparticulates 62.17 kg h^-1, Cr 6.217 kg h^-1, Fe 2.423 kg h^-1, Zn42 mg h^-1 and 6 mg h^-1 for Cu. Particulate matter was emitted at arate of 289 mg m^-3 from stack number 2. This value exceeds thelegal limit of 200 mg m^-3. Chromium and iron are the metalsin the largest amounts. The particles that constitute the largestproportion of the dust were in the range of 58-107.5 m. Thisis a characteristic feature of the particulate matter emissionsfrom ZIMASCO. Soils in the downwind direction from the smelterwere polluted with Cr up to a distance of about 700 m outward fromthe perimeter of the boundary of the smelter.