Mineral Beneficiation is any process that improves the economic value of the ore by physical and chemical methods by removing the gangue minerals to increase the concentrate enrichment (A. Gül et.al, 2010). Gold (Au) is a significant element found in nature both as native and as compounds with other elements and used for wide applications (Norgate and Haque, 2012). Based on its mode of occurrence, gold can be classified as visible gold, refractory gold and surface adsorbed onto other minerals (Joe Zhou et.al, 2004). Gold-bearing ores can generally be classified into placers, free-milling, oxidized, silver-rich, gold antimonides, gold bismuthites, gold sulfides, gold selenides, copper- sulphides, gold tellurides, and carbonaceous ores based on their mineralogical characteristics (A. Gül et.al, 2010).
Gravity separation, flotation, cyanidation, or combinations of these processes is typically used in the beneficiation and processing of gold bearing ores (A. Gül et.al, 2010; Liipo, 2003).
The physical, chemical and mineralogical characteristics of the gold and associated gangue minerals of specific deposit often determine best gold ore processing techniques (A. Gül et.al, 2010; Ogundare et.al, 2014). However, gold bearing ores requires an appropriate processing method which is environmentally benign (Gerardo et.al, 2021). Conventional gold processing method with aid of chemicals poses a risk on human health and environment (Gerardo et.al, 2021; Pulungan et.al, 2019; Youlton.et.al, 2021; Friedhelm.et.al, 2000; Ogundar et.al, 2014; Hylander.et.al, 2006).
Gravity separation is one of gold ore beneficiation method depending on the size, shape and density characteristics of gold and associated minerals (Gerardo et.al, 2021). Gravity concentration techniques are environmentally benign method for the beneficiation of gold-bearing ores and useful in situations where the ores are not amenable to flotation or where the use of cyanide is not desirable due to environmental concerns (Murphy et.al, 2012; Meza et. al, 2004; Egbe.et.al, 2013). Gravity separation is one of a commonly used technique in gold ore beneficiation due to its effectiveness in concentrating the gold particles and removes the unwanted gangue minerals based on their densities. This effectiveness of gravity separation depends on factors such as the size, shape and liberation characteristics of gold particles and other associated minerals in the ore (Gerardo et.al, 2021; Wotruba and Müller 2001). Gravity concentration method remains the dominant and important mineral beneficiation method and does not lost its importance despite widespread use of flotation and cyanidation beneficiation methods, as well as hydrometallurgical processes, due to a substantial improvement is made to gravity concentration methods to boost its efficiency and effectiveness through technological advancements (Zhixian Xiao 2001).
Jigs, pinched sluices, shaking tables, spirals, Knelson concentrator, Falcon concentrator, and multi-Gravity separator are among some of gravity concentrating tools that have been developed and utilized in the gold processing (Zhixian Xiao 2001; Emre. et.al, 2022; A. Gül et.al, 2010; Avimanyu et.al, 2018). All methods of gravity separation processing approach are being highly productive and environmentally benign and friendly. Gravity separation is always the first consideration in any flow sheet development program when there are substantial variances in the specific gravities of the valuable and gangue minerals (Murphy et.al, 2012).
The main objective of the previous works on the Ashashire Gold ore deposit, which located in the Benishangul Gumuz Region of western Ethiopia, were to locate economic gold deposit and to determine grade and tonnage of deposit however; they did not mention processing option for this specific deposit (Jelenc, 1966; EIGS-UNDP, 1972; MMAJ, 1974; Chewaka S, and de Wit, 1981; EMRDC, 1982; Jembere M, 1984; GSE, 1991 and 1995; GSR, 1996; BGME, 2013; Abebe Bedasa, 2014; Leta Amane, 2016; Sewagegn, 2020).
This project study focused on the investigating the applicability of the gravity separation method specifically to the Ashashire gold ore deposit, from Benishangul gumuz Region, western Ethiopia. This procedure involved analyzing the optimum particle size for the deposit to achieve high recovery of gold using gravity separation method. Additionally, the gold and associated elemental contents of the ore deposit were analyzed to assess the potential economic viability of the deposit. By analyzing particle size and elemental contents of the ore, the appropriate size fraction for effective separation based on the specific characteristics of the deposit and presence of other elements that may affect the processing were determined.