Tirivaviri Augustine Mamvura

@biust.ac.bw

Senior Lecturer, Faculty of Engineering and Technology
Botswana International University of Science and Technology



           

https://researchid.co/atmamvura

RESEARCH, TEACHING, or OTHER INTERESTS

Chemical Engineering, Waste Management and Disposal, Renewable Energy, Sustainability and the Environment, General Chemical Engineering

31

Scopus Publications

Scopus Publications

  • Exploring Low-Grade Iron Ore Beneficiation Techniques: A Comprehensive Review
    Mompati Mpho Bulayani, Prasad Raghupatruni, T. Mamvura and G. Danha

    The beneficiation of low-grade iron ores is a key research and development topic in the mineral processing industry. The gradual exhaustion of high-grade iron ore reserves, and rising consumer iron and steel demand globally necessitate efficient low-quality iron ore beneficiation to meet steelmaking quality requirements. This comprehensive review explores various beneficiation techniques for low-quality iron ore, focusing on conventional methods including comminution, froth flotation and gravity separation. This article discusses the principles, processes, and equipment used in these techniques and highlights recent advancements and research efforts in the field. This review also emphasizes the importance of effective beneficiation processes in enhancing economic viability, sustainable resource management, and environmental conservation. Furthermore, it presents a case study of iron ore deposits in Botswana, highlighting the potential economic growth and sustainable development that can be achieved by maximizing resource utilization through reductive roasting, followed by magnetic separation of iron ore using semi-bituminous coal as a reductant. Overall, this review provides valuable insights into low-grade iron ore beneficiation techniques and their significance in meeting the growing demand for high-quality iron and steel products.

  • Reclamation of iron and copper from BCL slag in Botswana
    T.S Gabasiane, G. Danha, T. Mashifana, and T. Mamvura
    Elsevier BV

  • A review of the combined torrefaction and densification technology as a source of renewable energy
    Thandiwe Sithole, Godwell Pahla, Tebogo Mashifana, Tirivaviri Mamvura, Elena-Niculina Dragoi, Anbalagan Saravanan, and Hasan Sadeghifar
    Elsevier BV


  • Application of Attainable Region Technique to Optimize Copper Slag’s Desired Size Class
    Tlotlo Solomon Gabasiane, Gwiranai Danha, Tirivaviri Mamvura, Tebogo Mashifana, and Vusumuzi Sibanda
    MDPI AG
    Copper slag is a hard material produced from smelting copper-bearing ores. Over the years, research has prioritized utilizing slag as a secondary source of base metals. This paper focuses on the grinding/milling of copper slag collected from the BCL Mine in Botswana to obtain a maximum amount of material in the desired size class with minimal energy consumption. This will then be followed by an integrated flotation and leaching approach of the desired size class material to recover copper. Our objectives are to determine the grinding time, ball loading, mill filling and desired size class for maximum recovery of copper mineral. The attainable region technique is an equipment-independent optimization tool employed here to determine the optimal specifications of our experimentally manipulated variables to satisfy the set objective function.


  • Overview of Torrefaction Technologies: A Path Getaway for Waste-to-Energy
    Tirivaviri A. Mamvura
    Springer International Publishing

  • Selective flocculation and recovery of chrome from plant slimes using starch and sodium oleate as flocculants
    V. Sibanda, LehAnA MAkARA, LeRATO SeBOSe, ThULAgAnyO SeTIMO, T. Mamvura and G. Danha
    Polish Academy of Sciences Chancellery
    plant in the north west province of South Africa was conducted using raw corn starch and sodium oleate as flocculants and sodium silicate a dispersant was applied on. Limited work has been reported on the flocculation of non-synthetic chrome slimes. The results showed that a slime sample with a chrome (Cr 2 O 3 ) head grade of 22.92% was upgraded to a maximum concentrate grade of 42.55% at a sodium oleate dosage of 88 g/ton slurry , a sodium silicate dosage of 44 g/ton slurry , 39.61% at a starch dosage of 106 g/ton slurry and sodium silicate dosage of 62 g/ton slurry . The corresponding recoveries using sodium oleate as a flocculent were between 80–89% and 73–79% for starch. Sodium oleate showed a better performance than starch in terms of both grade and recovery. Decantation washing tests showed that the chrome (Cr 2 O 3 ) grade of the concentrate can be further increased to above 44%. These results are very encouraging as they indicate that selective floccula - tion can achieve satisfactory upgrade ratios and recovery when processing chrome ultrafine or slime material.

  • Environmental and socioeconomic impact of copper slag—A review
    Tlotlo Solomon Gabasiane, Gwiranai Danha, Tirivaviri A. Mamvura, Tebogo Mashifana, and Godfrey Dzinomwa
    MDPI AG
    Copper slag is generated when copper and nickel ores are recovered from their parent ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. Slag is a major problem in the metallurgical industries as it is dumped into heaps which have accumulated into millions of tons over the years. Moreover, they pose a danger to the environment as they occupy vacant land (space problems). Over the past few years, studies have been conducted to investigate the copper slag-producing outlets to learn their behavior, as well as properties of slag, to have the knowledge of how to better reuse and recycle copper slag. This review article provides the environmental and socioeconomic impacts of slag, as well as a characterization of copper slag, with the aim of reusing and recycling the slag to benefit the environment and economy. Recycling methods are considered an attractive technological pathway for reducing waste and greenhouse gas emissions, as well as promoting the concept of circular economy through the utilization of waste. These metal elements have value depending on their characteristics; hence, copper slag is considered as a secondary source of valuable metals. Some of the pyrometallurgical and hydrometallurgical processes to consider are physical separation, magnetic separation, flotation, leaching, and direct reduction roasting of iron (DRI). Some of the possible metals that can be recovered from the copper slag include Cu, Fe, Ni, Co, and Ag (precious metals).

  • A comparative study on the comminution behavior of diorite rocks
    Gaesenngwe Gaesenngwe, Tirivaviri Mamvura, Gwiranai Danha, and Vusumuzi Sibanda
    Elsevier BV

  • Characterization of copper slag for beneficiation of iron and copper
    T.S. Gabasiane, G. Danha, T.A. Mamvura, T. Mashifana, and G. Dzinomwa
    Elsevier BV

  • Investigating the effect of lip froth washing on coal yield during flotation of a high ash South African coal
    Cherryl du Plessis, Vusumuzi Sibanda, Marek Dworzanowski, Gwiranai Danha, and Tirivaviri Mamvura
    Politechnika Wroclawska Oficyna Wydawnicza
    An investigation was conducted to evaluate the effect of lip washing on coal flotation at Anglo American’s Goedehoop South (GHS) fine coal plant in South Africa. In the test-work, performance of cells with lip washing system were compared with baseline cells without lip washing in terms of coal yield and coal quality. Yields observed with lip washing were significantly higher than those of baseline cells. Improvements of up to 15% were recorded. The product obtained at low flotation reagent dosages (1.30–1.45 kg/t) on lip wash cells had ~16.85% ash content against ~17.65% with baseline cells, suggesting that higher yields could be achieved at superior qualities to those achieved with baseline cells. At higher reagent dosages (1.60–1.75 kg/t), coal yields further improved but quality reduced on lip wash cells. Calorific Values (CV) of coal products obtained by lip washing and baseline flotation were similar. When different coal particle size fractions were floated separately, the yield increased as particle size increased from 75 to 300 μm and then decreased from 300 to 500 μm for both baseline and lip washing flotation. Lip washing caused a marked increase in the yield for finer particles (< 300 μm) with optimum size class of between 212 – 300 μm. In addition, a much bigger increase in the yield was achievable with lip washing of lower quality coal. The ash content after lip washing of poor-quality coal were also comparable to the ash content after lip washing of good quality coal.

  • Adsorption of lead ions from wastewater using nano silica spheres synthesized on calcium carbonate templates
    Milton Manyangadze, Nyaradzai M.H. Chikuruwo, T. Bala Narsaiah, Ch. Shilpa Chakra, Gratitude Charis, Gwiranai Danha, and Tirivaviri A. Mamvura
    Elsevier BV

  • Integrated and consolidated review of plastic waste management and bio-based biodegradable plastics: Challenges and opportunities
    Zvanaka S. Mazhandu, Edison Muzenda, Tirivaviri A. Mamvura, Mohamed Belaid, and Trust Nhubu
    MDPI AG
    Cumulative plastic production worldwide skyrocketed from about 2 million tonnes in 1950 to 8.3 billion tonnes in 2015, with 6.3 billion tonnes (76%) ending up as waste. Of that waste, 79% is either in landfills or the environment. The purpose of the review is to establish the current global status quo in the plastics industry and assess the sustainability of some bio-based biodegradable plastics. This integrative and consolidated review thus builds on previous studies that have focused either on one or a few of the aspects considered in this paper. Three broad items to strongly consider are: Biodegradable plastics and other alternatives are not always environmentally superior to fossil-based plastics; less investment has been made in plastic waste management than in plastics production; and there is no single solution to plastic waste management. Some strategies to push for include: increasing recycling rates, reclaiming plastic waste from the environment, and bans or using alternatives, which can lessen the negative impacts of fossil-based plastics. However, each one has its own challenges, and country-specific scientific evidence is necessary to justify any suggested solutions. In conclusion, governments from all countries and stakeholders should work to strengthen waste management infrastructure in low- and middle-income countries while extended producer responsibility (EPR) and deposit refund schemes (DPRs) are important add-ons to consider in plastic waste management, as they have been found to be effective in Australia, France, Germany, and Ecuador.


  • The development of a waste tyre pyrolysis production plant business model for the gauteng region, South Africa
    Nhlanhla Nkosi, Edison Muzenda, Tirivaviri A. Mamvura, Mohamed Belaid, and Bilal Patel
    MDPI AG
    Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks to critically evaluate the feasibility of constructing and operating a waste tyre processing facility and then subsequently marketing and selling the pyrolysis secondary end products by developing a financial business model. The model encompasses costing, procurement, installation, commissioning, and operating a batch pyrolysis plant in Gauteng, South Africa. To achieve the study objectives, an order of magnitude costing method was used for model construction. The results showed the feasibility and sustainability of operating a 3.5 tonne per day batch waste tyre pyrolysis plant in Gauteng Province, South Africa, with a 15-year life span and a projected payback period of approximately 5 years. It was concluded that for the pyrolysis plant to be successful, further treatment steps are required to improve the process economics; also, a stable and sustainable product market should exist and be regulated in South Africa.

  • Production of modified bitumen from used engine oil, coal tar and waste tyre for construction applications
    Nyaradzo Kamoto, Joseph Govha, Gwiranai Danha, Tirivaviri Mamvura, and Edison Muzenda
    Elsevier BV

  • Optimization of pulp production from groundnut shells using chemical pulping at low temperatures
    P. Musekiwa, L.B. Moyo, T.A. Mamvura, G. Danha, G.S. Simate, and N. Hlabangana
    Elsevier BV


  • Characterization of botswana coal from two coal fields: Mabesekwa and mmamabula to determine its coal rank
    Mmoloki Makoba, , Taboka Moalosi, Paul S. Agachi, Edison Muzenda, Tirivaviri A. Mamvura, , , , ,et al.
    Babes-Bolyai University


  • Production of activated carbon from poultry feathers for waste water treatment
    Rue Chiramba, Gratitude Charis, Nonhlanhla Fungura, Gwiranai Danha, and Tirivaviri Mamvura
    IWA Publishing
    Abstract Contamination of water bodies by heavy metal ions is a challenge many developing nations like Zimbabwe face, with negative environmental and socio-economic repercussions. Treating affected bodies usually requires a costly consignment of chemicals and activated carbon. This research investigates the possible use of an abundant waste resource – poultry feathers – to make activated carbon for heavy metal ion removal. Poultry consumption in this nation generates more than five million tonnes of feathers a year, with very few uses of this by-product. This research was carried out to evaluate the effectiveness of activated carbon synthesized from poultry feathers with sodium hydroxide as the activating agent. It was tested for removing heavy metal ions from waste water at Lake Chivero and the experimental work done showed that it had a removal efficiency as high as 97%, with a high affinity for lead ions as compared with chromium ions. Upon characterization, the activated carbon showed an iodine number of 520 mg and it worked best at a pH value of 8. The efficiency removal also increased with increasing adsorbent concentration as well as contact time up to a period where these factors ceased to be the limiting factors of the reaction.



  • Energy changes during use of high-power ultrasound on food grade surfaces
    Tirivaviri A. Mamvura, Sunny E. Iyuke, and Anthony E. Paterson
    Elsevier BV