News Update on Minerals Engineering : Dec 2020

Fire-resistant geopolymer produced by granulated blast furnace slag

This paper describes research into the use of granulated blast furnace slag as an active filler in the making of geopolymers. During this work it was found that geopolymer setting time correlates well with temperature, potassium hydroxide concentration, metakaolinite and sodium silicate addition. The physical and mechanical properties of the geopolymer also correlated well with the concentration of alkaline solution and the amount of metakaolinite that is added. The highest compressive strength achieved was 79 MPa. For fire resistance tests, a 10 mm thick geopolymer panel was exposed to a 1100 °C flame, with the measured reverse-side temperatures reaching less than 350 °C after 35 min. The products can be fabricated for construction purposes and have great potential for engineering applications. [1]

Microwave treatment of minerals-a review

This paper presents a review of the advances in the microwave treatment of minerals from the early stages of development to possibilities for future utilisation. Many different applications are considered, including fundamental heating rate studies, microwave assisted grinding, possible exploitation in the area of extractive metallurgy and also microwave treatment of coal. Conclusions are presented regarding the need for further fundamental and pilot scale data. Further indications of the potential for the commercial exploitation of microwaves within the mineral processing and extractive metallurgical industries have been included. [2]

Geopolymerisation of multiple minerals

Geopolymerisation can transfer large scale alumino-silicate wastes into value-added geopolymeric products with sound mechanical strength and high acid, fire and bacterial resistance. However, due to the complexity of source materials as well as the interaction between source materials during the geopolymerisation, previous studies have mostly dealt with single or bi-component systems, which could potentially narrow the application of this technology. The present work selects three industrial materials, i.e. fly ash, kaolinite and albite to investigate various combinations. The results show that when appropriate reaction parameters are used, the three component system gives geopolymers possessing the highest compressive strength and the lowest probability of cracking. It is believed that the higher reactivity of the fly ash and albite, the interaction between the source materials and the gel phase, and the reinforcing effect caused by the large unreacted albite particles are responsible for this satisfactory mechanical behaviour. [3]

Improvement of Yield and Mineral Content in Two Cultivars of Vicia faba L. Through Physical and Chemical Mutagenesis and their Character Association Analysis

World is continuously facing the food insecurity and malnutrition problem. Scientists all over the world are busy in developing the latest and innovative approaches for reducing the hunger and malnutrition problem which are increasing at an alarming rate throughout the world. The current experiment was conducted to improve the yield and nutritional quality of two cultivars of faba bean viz., Vikrant and PRT-12. The seeds of two cultivars were treated with single and combined treatments of gamma rays and ethyl methanesulphonate (EMS) in M1 generation. The seeds collected from M1 plants were sown to raise the M2generation. High yielding plants from lower treatments of gamma rays, EMS and their combinations were analyzed for yield and different mineral elements like zinc, iron and manganese using atomic absorption spectrophotometer (AAS). Both cultivars showed significant increase in yield and mineral content. Variety Vikrant showed more increase in yield and mineral content towards mutagen treatments than PRT-12. This approach can be utilized on other plants to improve the yield and nutritional quality of plants. This will overcome the increasing rate of hunger and malnutrition problem throughout the world. [4]

Deposition and Characterization of Silver Oxide from Silver Solution Recovered from Industrial Wastes

Aims: To recover silver from industrial waste and use its solution in silver oxide deposition.

Study Design: Extraction, electrodeopsition on different substrates, XRD and topographical characterizations.

Place and Duration of Study: Sample: x-ray films were collected from Anambra State University Teaching Hospital, Awka, Nigeria. Electrodeposition at Physics and Industrial Physics Department, Nnamdi Azikiwe University, Awka. XRD characterization was done at Energy centre, Obafemi- Awolowo University, Ile-Ife, Nigeria in September.

Methodology: Silver was recovered from x-ray films by dissolving the silver compounds with concentrated nitric acid. The solution thus formed was used as electrolyte in the electrodeposition of silveroxide. Two metallic substrates (zinc and lead) were used for the electrodeposition both serving as cathode while a copper electrode served as the anode. Structural and topographical characterizations were done using XRD and micrograph techniques.

Results: From the result, it was observed zinc substrate gave a good deposition of silver oxide without any impurities whereas the lead substrate gave deposition of silver oxides with lots of impurities

Conclusion: Silver was successfully recovered from wastes and the solution used in silver-oxide deposition. [5]

Reference

[1] Cheng, T.W. and Chiu, J.P., 2003. Fire-resistant geopolymer produced by granulated blast furnace slag. Minerals engineering, 16(3), pp.205-210.

[2] Kingman, S.W. and Rowson, N.A., 1998. Microwave treatment of minerals-a review. Minerals Engineering, 11(11), pp.1081-1087.

[3] Xu, H. and Van Deventer, J.S., 2002. Geopolymerisation of multiple minerals. Minerals engineering, 15(12), pp.1131-1139.

[4] Khursheed, S., Raina, A. and Khan, S. (2016) “Improvement of Yield and Mineral Content in Two Cultivars of Vicia faba L. Through Physical and Chemical Mutagenesis and their Character Association Analysis”, Archives of Current Research International, 4(1), pp. 1-7. doi: 10.9734/ACRI/2016/24802.

[5] E. Ekpunobi, U., K. Okwukogu, O., I. Anozie, A., S. Ogbuagu, A., I. Ajiwe, V. and I. Nweze, C. (2013) “Deposition and Characterization of Silver Oxide from Silver Solution Recovered from Industrial Wastes”, Chemical Science International Journal, 3(3), pp. 307-313. doi: 10.9734/ACSJ/2013/3214.

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