Browsing by Author "Ntalikwa, Justin William"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Gold recovery by cyanide leaching: A case study of small scale miners in Tanzania(Open Science, 2015) Ntalikwa, Justin WilliamIn this study, sodium cyanide leaching technology has been used to recover gold from tailings that are used by Mawelo small scale miners, located in Chunya district, Mbeya region, Tanzania. The sample collected was sent for analysis of mineralogical composition and average particle size. The fractions retained on each sieve, which ranged 180 – 500 μm were used in the leaching experiments. The leaching was implemented using sodium cyanide with concentration in the range of 500 – 1200 ppm, the pH of the reaction mixture was maintained in the range of 10.2 to 10.5 by addition of 5 g of lime (CaO). The retention time spanned the range of 24 to 96 hours. It was observed that the average particle size, P80 (80% of material passing) of the sample was 480 μm this was not equal to the liberation size of the sample. In order to increase the gold recovery, grinding of the sample to 180 μm is required. The mineralogical composition of the sample revealed: gold: 5.85 g/t, copper: 150 ppm, sulphur: < 0.01 ppm, arsenic: 1.82 ppm, cobalt: 18.25 ppm and nickel: 23. 89 ppm. With 180 μm particle size, the cyanide dosage in the range of 700-1000 ppm, retention time of 72 hrs, gave a gold recovery of 2.45 ppm which was better than all parameters studied but represented 42% of the gold recovery in the sample. From this study it is evident that analysis of the mineralogical composition of the ore and attaining its liberation size are mandatory requirements to effective and efficient cyanide leaching process.Item Producing sulphuric acid in Tanzania and potential sources: A review(Open Science, 2014) Hiji, Morris Frank; Ntalikwa, Justin William; Vuai, Said AliSulphuric acid is a backbone of chemical industry, agriculture and energy sectors. Tanzania has potential sources of producing its own sulphuric acid. The three most common methods: contact process, wet process and lead chamber process of producing sulphuric acid are reviewed. A modified lead chamber method can be a preferred method of producing the mineral acid by using local available raw materials according to Tanzania environment. Among of raw materials, pyrites from Samena area in Geita Region, Tanzania are the most potential, although there are also other sources from operating gold mines. Production of sulphuric acid in Tanzania could make a meaningful contribution to country economy.