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The main objective of the current work is to recover SiO 2 various acid concentrations, scrubbing time, and attrition impeller speed for crystal glass application. Silica rocks were treated using a physico-chemical method involving physical separation method using citric and sulphuric acids as the reagents. Low acid concentration range of 1%-2% and variable scrubbing time of 10, 20, and 30 min were investigated. The microstructure, phase, and particle size of the silica rocks were determined after scrubbing process. Citric acid was found effective in improving the purity of SiO 2 to 99.8% at 0.75% concentration, via a 20 min scrubbing process operated at 1,250 rpm (rotations per minute). The phase structure and morphology of the recovered SiO 2 were confirmed as trigonal crystal structure with small and irregular shape. To date, studies on the processing of silica rock using organic acid are yet very limited.

Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre AIP Conference Proceedings 1669, 020010 (2015) Abstract. Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X-and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containing crushed granite.

The silica sand deposit located at km 55 Jalan Pantai Kuala Terengganu-Kuala Besut in the District of Setiu, North Terengganu consists of loose sand of fine to coarse grain size which is developed over the raised beaches of marine origin. The underlying bedrock is believed to be either metasediment of Late Paleozoic age or intrusive granitic rocks. The average content of SiO 2 is 99.3% while for the Fe 2 O 3 , Al 2 O 3 and TiO 2 , their average content are 0.1%, 0.3% and 0.2% respectively. The screen analyses show that more than 90 percent of the silica sand is within 150 to 1,180 micron size range. The total area underlain by potential silica sand is about 1.9 million sq. metres with total measured reserve about 2.6 million tonnes. According to Malaysian Standard, MS 701:1981 and British Standard BS 2975:1988, silica sand for making crystal glass should meet the grade B specification in which the purity of silica sand is not less than 99.5% with only a small amount of iron oxide (0.015%), alumina (0.05%), chromium oxide (maximum 2 ppm) and other mineral oxides. In the production of crystal glass, a front loading furnace was used and maximum melting temperature was 1400 °C. After melting process, physical evaluation on the crystal glass products were performed pertaining to complete accomplishment of melting such as existing of bubbles inside crystal glasses. In order to ensure that crystal glass quality meets the international standard, specification for crystal glass published by British standard BS 3828:1973 was taken as a guideline. Some of the parameters are density, surface hardness and refractive index. In general, silica sand from Gong Belibis, Setiu Terengganu is suitable as a raw material for making crystal glass product.

Abstract. Gamma rays are better absorbed by materials with high atomic numbers and high density. Steel, lead, depleted uranium, concrete, water or sand can be used as gamma shielding. Lead and steel are normally used for making doors of the bunker and to reduce radiation scatter. Depleted uranium is used for gamma container. Water is used in nuclear reactor as neutron and gamma absorber. Sand is used for mobile hot cell. However concrete is the most common and cheap material for gamma radiation bunker. In this research, concrete made from hematite aggregates was used to make chevron blocks for a temporary construction of labyrinth bunker. This paper explains and discusses the gamma attenuation around labyrinth bunker with concrete containing hematite aggregates.