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Review Article
Defect Assessment with DAC and DAM Methods; Measurement Accuracy Problems
Tranca Theodor*,
Tranca Mircea,
Cucuzel Cătălin Vasile
Issue:
Volume 10, Issue 4, December 2025
Pages:
89-95
Received:
26 May 2025
Accepted:
7 July 2025
Published:
9 October 2025
Abstract: Conventional pulse-echo ultrasonic inspection uses the ratio of the signal from a crack-like defect to the signal from a reference reflector as one factor which determines whether the flaw merits reporting, further sizing, and, possibly, removal. As these defects are smooth, on the scale of an ultrasonic wavelength, and generally flat, and also large relative to the wavelength, they can be successfully modelled using the geometrical theory of diffraction (GTD). GTD is a rapid method for evaluating the ultrasonic signal from a defect. The signal from the reference reflector is easy to calculate if the reflector is a side-drilled hole whose axis is normal to the ultrasonic beam axis and provided it is in the far field of the transducer. If the reference reflector is a flat-bottomed hole then prediction of the signal for non-normal angles of incidence is more difficult since the signal arises from the curved edge at the intersection of the flat bottom of the hole and its cylindrical side face.
Abstract: Conventional pulse-echo ultrasonic inspection uses the ratio of the signal from a crack-like defect to the signal from a reference reflector as one factor which determines whether the flaw merits reporting, further sizing, and, possibly, removal. As these defects are smooth, on the scale of an ultrasonic wavelength, and generally flat, and also lar...
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Research Article
The Establishment, Designation, and Management of an Artisanal and Small-Scale Gold Mining Cluster Zone: Case Study of the Odo Shakiso District, Oromia, Ethiopia
Misganu Kabeta*
,
Gera Techane,
Adisu Misgana
Issue:
Volume 10, Issue 4, December 2025
Pages:
96-109
Received:
28 August 2025
Accepted:
16 September 2025
Published:
17 October 2025
Abstract: Artisanal and small-scale mining (ASM) encompasses informal or formal operational mining activities that primarily use traditional tools and simple methods and techniques for resources of earth extraction, transportation and processing. ASM generally, requires minimal operational capital investment and is typically characterized by low capital, intensive labor worker and comprises an individual’s working as private or in family groups, as well as in partnerships, or as members of cooperatives in legal associations and enterprises. Ethiopia is one of a developing country, endowed with different mineral resources, where ASM was the most common practice among the people who live in rural parts of the country next to agriculture. Despite the ASM methods being traditional, mining activity practices were wasteful nature and abounding with so many obstacles and miners were making effort to continue their work of extract minerals primarily focuses on mining precious metals like gold, platinum, tantalum, lithium, copper, gemstones and semiprecious gemstones like opal, emerald, sapphire, aquamarine, amazonite, and other semiprecious type of gemstone, industrial minerals like clay, crushed stone, diatomite, gypsum, salt, sand, silica sand. A huge number of ASM’s in Ethiopia still face significant obstacles/challenges including a lack of the best mining and processing practices, low degree of capitalization and mechanization, limited financial access, lack of training on capacity building to increase production and productivity, inadequate environmental impact reduction measures, and limited access to marketing opportunities. Ethiopia is now implementing several initiatives/ measures which support the growth of ASM industry sector to revitalize the ASM with its main goal. To fully benefit from ASM, the government must work on ASM formalization through the novel idea of cluster and manage. To gradually transform/turn ASM into ASSM support them by suiting conditions on how to get equipments through rent approach, link with technology manufacturing industry and additionally provide training on sustainable mining and processing technology in the process of ASM transformation.
Abstract: Artisanal and small-scale mining (ASM) encompasses informal or formal operational mining activities that primarily use traditional tools and simple methods and techniques for resources of earth extraction, transportation and processing. ASM generally, requires minimal operational capital investment and is typically characterized by low capital, int...
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Review Article
Artisanal and Small-Scale Gold Mining in Ethiopia: A Comprehensive Review of the Sector's Trend, Performance and Potential
Misganu Kabeta*,
Gera Techane
Issue:
Volume 10, Issue 4, December 2025
Pages:
110-129
Received:
22 August 2025
Accepted:
12 September 2025
Published:
18 October 2025
Abstract: Mining is the backbone for ASGM community livelihood and it is a difficult and risky occupation operated without guarantee. Artisanal and small-scale mining in Ethiopia was poor industry dominated by a large number of unskilled and semi-skilled labor force. Because of vast informal engagement, ASGM history has not been properly recorded. Though the ASGM provides employment for a million peoples directly and indirectly in Ethiopia, mainly it operates informally, working without license, lack legal protection, and government support and not complying with government regulations and environmental mitigation matters. The legal enforcement level of proclamations is weak. Nearly all ASGM miners use manual tools in the country, and this strictly need technology interventions. Proclamation, regulations, laws, guidelines, policy and directives pertaining to ASGM on mining, environment, and related issues should be reviewed. This review article based on the previous study in assessing and analyzing ASGM sector in Ethiopia by addressing technical, legal, economic, and social factors. This aimed to gather information on ASGM in Ethiopia and assess previous study to improve productivity and market links, and promote sustainable development in the ASGM sector. The study revealed that the ASGM sector in Ethiopia remains underdeveloped, with minimal contribution to country’s GDP. Indeed, this review cannot go by without appreciating the current awareness and alertness that is happening within ASGM sector.
Abstract: Mining is the backbone for ASGM community livelihood and it is a difficult and risky occupation operated without guarantee. Artisanal and small-scale mining in Ethiopia was poor industry dominated by a large number of unskilled and semi-skilled labor force. Because of vast informal engagement, ASGM history has not been properly recorded. Though the...
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Research Article
Gold Recovery from Cyanide-Based Leach Solutions Using Zinc Cementation: A Case of Small-scale Gold Mining in Zimbabwe
Issue:
Volume 10, Issue 4, December 2025
Pages:
130-142
Received:
12 September 2025
Accepted:
23 September 2025
Published:
29 October 2025
DOI:
10.11648/j.ijmpem.20251004.14
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Views:
Abstract: The small-scale gold mining sector (SSGM) in Zimbabwe is a significant contributor to the country’s economy, at 12% of total exports. Although official output figures are rising, the general belief is that most of the small-scale gold production is unaccounted for, as it only reports gold produced from amalgamation and carbon adsorption, which the Government monitors through Statutory Instruments. However, gold produced from unregulated methods often ends up in illicit gold trading, with Zinc cementation being one of the unregulated gold recovery methods that small-scale gold miners rampantly abuse due to its ease of filtration and low cost. Governing legislation or Statutory Instruments for control of Zinc cementation are non-existent, creating easy loopholes for abuse and strong links to illicit financial flows. This study investigates the feasibility of regularising Zinc cementation as a gold recovery method for small-scale operations in Zimbabwe, ensuring effective monitoring and surveillance. Optimum parameters for Zinc cementation were determined experimentally. The determination of optimum parameters for Zinc cementation was done using a 23 fractional factorial design and gold deportment analysis was conducted using samples from a small-scale gold mine located on the early Precambrian, Bulawayan, andesitic and dacitic meta-volcanic geological formation in Zimbabwe’s Matabeleland mining region. The influence of free cyanide concentration, dissolved oxygen concentration and pH on gold recovery was evaluated. Experimental work showed the feasibility of using Zinc Cementation as a possible recovery route for gold in SSGM with optimum parameters of: - pH value 11.5, free cyanide concentration 0.05g/L and dissolved oxygen concentration of 0.5ppm. The analysis showed that pH and Oxygen concentration increase gold recovery by a factor of 40%, with pH having the most significant effect on gold recovery. The study concludes that Zinc Cementation for small-scale hydrometallurgical gold extraction is an effective recovery method and should be regularised by the Government through a Statutory Instrument for easier monitoring and surveillance. Further studies on various ores from different provinces are recommended to incorporate diverse mineralogical differences into the design. Additionally, setting up a pilot plant to refine the metallurgical plant requirements for controlling zinc cementation is suggested.
Abstract: The small-scale gold mining sector (SSGM) in Zimbabwe is a significant contributor to the country’s economy, at 12% of total exports. Although official output figures are rising, the general belief is that most of the small-scale gold production is unaccounted for, as it only reports gold produced from amalgamation and carbon adsorption, which the ...
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Research Article
Effective Treatment of Acidic Effluent Generated from Li-ion Battery Recycling
Issue:
Volume 10, Issue 4, December 2025
Pages:
143-159
Received:
23 September 2025
Accepted:
9 October 2025
Published:
30 October 2025
DOI:
10.11648/j.ijmpem.20251004.15
Downloads:
Views:
Abstract: The present study investigates a comprehensive treatment strategy for managing acidic effluent generated during the hydrometallurgical processing of discarded lithium-ion batteries (LIBs), specifically following cobalt oxalate precipitation. The effluent, characterized by extremely low pH (0.1), high total dissolved solids (TDS = 50,000 mg/L), and elevated chemical oxygen demand (COD = 1640 mg/L), was treated through a sequential combination of coagulation, adsorption, and distillation. Coagulation using ferric sulfate achieved 34% TDS reduction through precipitation of dissolved metal ions and oxalates. Subsequent adsorption employing thermally activated carbon derived from waste RO filters further reduced TDS by ~55% due to enhanced surface area and porous structure. Final distillation at 150°C yielded a >99% decrease in TDS and COD, producing condensate meeting CPCB discharge standards (TDS = 79 mg/L, COD = 32 mg/L). The integrated approach effectively transformed a high-strength acidic effluent into reusable water while concentrating recoverable metal residues. A preliminary techno-economic assessment indicated that the process is technically viable and scalable, with energy consumption during distillation being the major cost factor. The study demonstrates a sustainable and resource-efficient treatment pathway for LIB recycling effluents, contributing toward circular economy and zero-liquid discharge objectives.
Abstract: The present study investigates a comprehensive treatment strategy for managing acidic effluent generated during the hydrometallurgical processing of discarded lithium-ion batteries (LIBs), specifically following cobalt oxalate precipitation. The effluent, characterized by extremely low pH (0.1), high total dissolved solids (TDS = 50,000 mg/L), and ...
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