Presentation on theme: "THE HALF-FILLED GLASS. Nova Scotian Crystal, founded in 1838 and considered one of the finest hand-cut crystal makers in the world, is located on the."— Presentation transcript:
Nova Scotian Crystal, founded in 1838 and considered one of the finest hand-cut crystal makers in the world, is located on the historic Halifax waterfront in Nova Scotia, Canada. Their work captures the beauty of 13th, 14th and 15th centuries Italian artisans using traditional techniques of mouth-blown, hand-cut crystal making that have been passed down from generation to generation of craftsmen whose lineage can be traced back to the greatest artists of Venice and Rome.
Nova Scotian Crystal glass owes its unique character to the ancient silica sands found along the coast of the Gulf of Oman. Most of the company’s silica sand shipments come from the United Arab Emirates which possess state-of-the-art silica sand processing plants located between Abu Dhabi and Sharjah
The major component of silica sand is Silica or silicon dioxide (SiO 2 ), a chemical compound consisting of one silicon and two oxygen atoms. Quartz is the most common sand forming mineral. If the particular sand deposit contains almost nothing but quartz, we often call it a silica sand. Such sand deposits are said to be mature because other rock forming minerals are already broken down by the weathering process leaving only the super-resistant quartz as a residue. Silica sand is a mineral resource. It is mined mostly for glass making.
Some beautiful beaches are made of silica sand. There are lots of light-colored beach sands around the world but many of them (especially in low latitudes) are made of small pieces of corals and other sea creatures. This sand is calcareous (composed of calcium carbonate) but some biogenic grains are siliceous as well. For example radiolarians (ameoboid protozoa) and diatoms (algae) have siliceous shells. Sometimes sandstone is said to be siliceous. What does that mean? It may be a sandstone which is cemented by the silica minerals quartz or chalcedony (cryptocrystalline quartz) or it could be a sandstone which is composed predominantly of silica minerals (although sometimes feldspars are included).
The preparation of sand for glass-making consists of five basic processes: natural decomposition, extraction, sorting, washing, and in some cases crushing. The first process, natural decomposition, usually takes millions of years. The other processes take considerably less time. The sand processing plant is located in the immediate vicinity of the natural deposit of material to minimize the costs of transportation. Most plants are stationary and may operate in the same location for decades. Some plants are mobile and can be broken into separate components to be towed to the quarry site. Mobile plants are used for remote construction projects, where there are not any stationary plants nearby. The capacity of the processing plant is measured in tons per hour output of finished product. Stationary plants can produce several thousand tons per hour. Mobile plants are smaller and their output is usually in the range of 50-500 tons (50.8-508 metric tons) per hour.
Wet processing is a major component of sand clarification. After initial crushing and screening, industrial sand and gravel are washed to remove unwanted dust and debris and are then screened and classified again. The sand (now containing 25 to 30 percent moisture) then goes to an attrition scrubbing system that removes surface stains from the material by rubbing in an agitated, high-density pulp. The scrubbed sand is diluted with water to 25 to 30 percent solids and is pumped to a set of cyclones for further desliming. If the deslimed sand or gravel contains mica, feldspar, and iron bearing minerals, it enters a froth flotation process to which sodium silicate and sulfuric acid are added. The mixture then enters a series of spiral classifiers where the impurities are floated in a froth and diverted to waste. The purified sand, which has a moisture content of 15 to 25 percent, is conveyed to drainage bins where the moisture content is reduced to about 6 percent. The material is then dried in rotary or fluidized bed dryers to a moisture content of less than 0.5 percent. The dryers generally are fired with natural gas or oil, although other fuels such as propane or diesel also may be used. After drying, the material is cooled and then undergoes final screening and classification prior to being stored and packaged for shipment. The washing process is very intensive and requires that the processing facility have direct access to a stable source of water. Like a number of other countries in the region, the Arab Emirates generates much of its water supply from desalination of seawater from the Persian Gulf and the Gulf of Oman.
Salt water is desalinated to produce fresh water suitable for human consumption, irrigation or any number of manufacturing processes that are water intensive. Most of the modern interest in desalination is focused on developing cost- effective ways of providing fresh water for human use in areas that have limited rainfall. Desalination is, therefore, particularly relevant to dry countries which have limited access to fresh water. According to the International Desalination Association, in June 2011, 15,988 desalination plants operated worldwide, producing 66.5 million cubic meters per day, providing water for 300 million people. Production is expected to reach 120 million m 3 by 2020; some 40 million m 3 is planned for the Middle East. The world's largest desalination plant, producing 640,000 m 3 per day, is the Jebel Ali Desalination Plant (Phase 2) in the United Arab Emirates The largest percent of desalinated water used in any country is in Israel, which produces 40% of its domestic water use from seawater desalination
Marine biologists warn that widespread desalinization can take a heavy toll on ocean biodiversity; as such facilities' intake pipes essentially vacuum up and inadvertently kill millions of plankton, fish eggs, fish larvae and other microbial organisms that constitute the base layer of the marine food chain. In addition, the salty sludge leftover after desalinization are sometimes disposed of indiscriminately and can wreak havoc on marine and coastal ecosystems if dumped haphazardly offshore. It is thought that the decline of some marine populations from discharge areas may be related to the salty outflow. There is evidence to suggest that the Jebel Ali Desalination Plant effluent has contributed to the expansion of several Salt Marshes east of the facility.
Nova Scotian Glass is concerned that the increased salinity of the effluent and the other corrosive byproducts produced by the Jebel Ali Desalination Plant are leaching into the sands used to make their high-quality crystal glassware. They are also concerned that expansion of the local salt marshes are having an impact as well.
MVHS financial has contracted with Nova Scotian to complete an analysis of the coastal sands to determine whether the percent composition of silica has been altered by the increased impact of the Jebel Ali Desalination Plant effluent on the local salt marshes. Initial reports suggest higher percentages of salt, iron fragments produced from the corrosion Associated with desalination and low-density particulates that have not het been identified. MVHS intends to establish the % composition by mass of each of the major components of the Emirate sand used by Nova Scotian. A decision will then be made as to whether to look for another source of sand. Low density particulates Fragmented iron Silica Sand Salt particulates Coastal sand sample