INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 6, ISSUE 03, MARCH 2017 ISSN 2277-8616 126 IJSTR©2017 www.ijstr.org The Suitability Of Local Quartz Sand In The Production Of Bath Crucibles. C. O. Okpanachi, S. I. Ibrahim, A. C. Okoro, K. Dogo, M. K. Idris Abstract: The suitability of local quartz sand in the production of bath crucibles is a study that was carried out in order to impart overall strength on bath crucibles, hence reduce breakages during fettling. Therefore, this research constitutes a study to enhance the efficiency of production of bath crucibles by addition of quartz sand in slip preparation. The steps taken in the beneficiation of quartz sand for the production of bath crucibles are comminution which entails crushing and milling, classification, washing, liquid dispersion, sizing and reduction of iron content by magnetic separation. The slip contains materials like plastic clay, feldspar, kaolin, talc, sodium silicate, water, quartz sand, etc. These were all milled in the ball mill for slip production, casting and fettling, glazing and sintering to get final bath crucibles as the end products. Quartz sand is used in a variety of products essentially as raw material for the foundry casting and glass industries and also in chemicals, water filtration and ceramics, the heat resistance nature of quartz sand makes it an excellent refractory substance for these industrial processes. Slip can be prepared for production of bath crucibles without the inclusion of quartz sand; however the addition of quartz sand is needed to improve the mechanical performance of the slip in the production of bath crucibles. Keywords: Quartz sand, Beneficiation, Bath crucible, Slip, Comminution, Fettling, Liquid dispersion. ———————————————————— 1 INTRODUCTION This paper highlights issues regarding the suitability of local quartz sand in the production of bath crucibles to aid in reduction of breakages during handling especially during fettling, and also to aid in vitrification during firing. Quartz sand was sourced from Kadna, Minna, Niger state, Nigeria, which lies within the coordinates of 09 0 37’N and 06 0 30’E [1]. Quartz is a crystalline silicate mineral with piezoelectric properties and it is the most abundant mineral on the earth’s surface. Quartz sand exhibit properties such as high thermal and chemical stability have a vitreous luster, specific gravity of 2.6 – 2.7 and mohs’ hardness of 7 which makes it very durable. It is chemically inert when it comes in contact with most substances and has electrical properties and heat resistance that make it valuable in electronic products. Its luster, colour, and diaphaneity make it useful as a gemstone, in making of glass and in ceramics [2]. A crucible is a cup-shaped piece of laboratory equipment used to contain chemical compounds when heated to extremely high temperature [3], crucibles and their lids can come in high or low form shapes and in various sizes but rather small (40-100ml) size porcelain crucibles are commonly used for gravimetric chemical analysis. Among others, [4], [5], [6], [7], [8], [9], [10,] have contributed to this study; however they based their work on the suitability of quartz sand for other industrial applications other than bath crucibles. To date, no study that evaluates the suitability of local quartz sand in the production of bath crucibles. Thus, this paper aims to investigate the effects of quartz sand on ceramic slip, how it affect the overall slip properties like linear shrinkage, water absorption capacity, bulk density, weight loss etc., and specifically on produced bath crucibles in terms of added strength and overall production efficiency. 2 MATERIALS AND METHODS A total of 533kg of raw materials comprising of plastic clay, feldspar, kaolin, talc, water, soda ash, sodium silicate, quartz sand etc., were charged into the ball mill for slip production after undergoing beneficiation process like crushing which entails the reduction of the particle size to between 0.3 meter (m) down to approximately 1 millimeter (mm). The materials were milled in the ball mill to as low as 1.0 micrometer to liberate impurities, facilitate mixing and produce a more reactive material for firing [11], [12,]. The slip obtained was sieved using the vibrating sieve of 300 mesh. Magnetic separation took place in the slip by the use of magnets to remove iron impurities. The slip was then stored in the storage tanks for maturity. Forming occurs, then the fine, platy morphology of clay particles were used to advantage in the forming of clay-based ceramic products. Depending on the amount of water added, clay- water bodies can be stiff or plastic. Plasticity arises by virtue of the plate- shaped clay particles slipping over one another during flow. With even higher water content and the addition of dispersing agent to keep the clay particles in suspension, readily flowable suspensions called slurry or slip was produced [13]. The suspension was then poured into porous plaster moulds where capillary forces suck the water into the moulds from the slip and causes a steady dispersion of clay particles in dense face to face packing, on the inside surface of the moulds. After a sufficient thickness of deposit has been obtained, the excess slip was drained and the moulds opened to reveal free standing clay pieces that can be dried or fired [14]. The bath crucibles were placed on a wooden board for 24hrs for air drying, followed by oven drying at 105 0 C for 6hrs in a process called convection to eliminate evaporable water. The bath crucibles were then fettled to remove the rough edges or surfaces or to modify the shape. Glaze was then applied to the bath crucibles by spraying and dipping. The raw materials used for glazes are quartz, feldspars, carbonates, borates and zircon [15]. The bath crucibles were thereafter, fired in the kiln (electric furnace) at 1156 0 C for 6hrs [14], where clay base ceramics undergo gradual heating to remove structural water, to decompose and burn off any organic binders used in forming, and to achieve consolidation of the ware. The process of vitrification takes place in the kiln and is aided by the deposited glaze _______________________  C. O. Okpanachi, S. I. Ibrahim, A. C. Okoro, K. Dogo, M. K. Idris  Scientific Equipment Development Institute, Minna, Nigeria obekpa@yahoo.com