14 Apr 2016

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  1. PRESENTATION ON ELECTRICITY Dedicated to beloved my family & faculty GYPSUM
  2. GYPSUM  Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrat, with the chemical formula CaSO4·2H2O  COLOR- Colorless to white; may be yellow, tan, blue, pink, brown, reddish brown or gray due to impurities.
  3. MANUFACTURING PROCESS OFCALCINED GYPSUM  The raw material gypsum is sorted and washed with water for removal of sand and other impurities.  The lumps thus obtained are then dried and powdered in pulverizer. The dried gypsum powder is calcined in a rotary drum calciner at a temperature of 160ºC to 180ºC.  The process of calcination is done over a period of about 2 hours. the temperature so that one and half molecules of water is removed to convert the gypsum (CaSo4 2 H2O) into plaster of Paris (CaSo4 ½ H2O).  After cooling the product (plaster of Paris) is further pulverized to a fineness of 150 mesh and packed in air tight polythene lined gunny bags to avoid the plaster of Paris from absorption of moisture. Raw material Water POP 160ºC to 180ºC washed crushing Calcination about 2 hrs. packing
  4. Advantage of p o p  It expands very slightly on setting. It is easy to spread and level.It mixes up easily with water. It has no appreciable chemical action on paint and does not cause alkali attack. Tiles and blocks of plaster of Paris have the specific advantage of lightness and high fire resistance. Plaster of Paris gives a decorative interior finish.
  5. Disadvantage of p o p  Gypsum plaster is not suitable for exterior finish as it can not be used in damp finish.  Cement can not be mixed with plaster of Paris.  It is more expensive than cement or cement lime plaster. The labor cost for applying plaster of Paris is high.
  6.  Gypsum is a rock like mineral commonly found in the earth’s crust, extracted, processed and used by Man in construction or decoration in the form of plaster and alabaster since 9000 B.C.. Plaster was discovered in Catal-Huyuk in Asia in an underground fresco, and in Israel Gypsum floor screeds were found from 7000 B.C. During the time of the Pharaohs, Gypsum was used as mortar in the construction of the Cheops Pyramid (3000 B.C.). In the Middle Ages and the Renaissance, decorations and artistic creations were made of plaster. Since then, the range of construction-related uses have continued to multiply. HISTORY OF GYPSUM
  7. Raw material 1.High-quality gypsum rock is extracted at quarries or mine crusher 2.Large rocks are crushed into small pieces Grinding mill 3.The mill reduces small rocks to a very fine, chalk-like powder called land plaster. Calcine system 4.The land plaster is heated in large kettles to remove most of the water from the plaster. Stucco holding tank 5.Calcined land plaster, called stucco, is fed from a holding bin to the mixer by a screw conveyor. mixer 6.In the mixer, water is added back to the stucco to form a slurry, and foam is added to the slurry to make the wallboard more lightweight. Forming station 7.T he board forming line starts with two large rolls of recycled paper or fiberglass mats. The slurry is poured onto the bottom sheet and is immediately covered by the facing sheet from the other roll. Board line 8. the board travels down a long conveyor line in a single continuous piece. During this trip, water rehydrates the stucco, causing it to harden. Cut –off knife 9. the end of the line, a blade cuts the hardened board into various lengths. Transfer table 10.Here the cut lengths are turned face-side up to protect the face paper or mat, then fed into the kiln. 11.Kiln The board kiln completes the drying process, leaving the gypsum board virtually moisture-free. MANUFACTURE OF GYPSUM board
  8. Major varieties of gypsum  Satin spar Pearly, fibrous masses  Selenite Transparent and bladed crystals  Alabaster Fine-grained, slightly colored SATIN SPAR ALABASTER ALABASTERSelenite Type of gypsum:-  Natural gypsum or,  Synthetic gypsum is k/n as fgd.
  9. Uses of gypsum Gypsum can be used :- architecture. Medical. Agriculture. Fine art. Chemical industry.  juice extraction of some fruits and vegetables. Cosmetic etc.
  10. Use of gypsum in building Gypsum building materials are used in all construction types (residential, non-residential, new or refurbished) Plasterboard Plasterboard is used for partitions and the lining of walls, ceilings, roofs. The properties of plasterboard can be modified to meet specific requirements , such as fire resistance, humidity resistance, shock resistance, etc.
  11. Decorative Plaster Plaster powder, mixed with water, manually or through the use of silo-supplied spray systems, are used to create an effective and aesthetically-pleasing lining for brick and block walls, and for ceilings.
  12. Building plaster Gypsum plaster is used for walls and ceilings.
  13. Plaster blocks Gypsum blocks are used for partitions and Gypsum tiles for ceilings.
  14. Gypsum Fibreboards Gypsum fibreboard is used for partitions and the lining of walls, ceilings, roofs and floors. Standard Gypsum fibreboard offers good performance when it comes to shock resistance, sound insulation and humidity resistance.
  15. Use of gypsum in medical  Gypsum is also used in the medical industry. Gypsum is also used to clean teeth and is present in many forms of toothpaste. It is used to set the broken bones & sprain. It is used in filling of teeth cavities.
  16. Use of gypsum in agriculture Be a source of Calcium and Sulphate Sulphur for plant growth. Gypsum is added to soil to make the soil better able to absorb moisture. Gypsum is used in water to settle dirt.
  17. Gypsum board  Gypsum board is the generic name for a family of panel products that consist of a non-combustible core. All gypsum panel products contain gypsum cores; however , they can be faced with a variety of different materials, including paper and fiberglass mats. Gypsum board is often called drywall, wallboard, or plasterboard.
  18. Standard size of gypsum board  Standard size gypsum boards are 48 inches wide and 8, 10, 12 or 14 feet long.  The 48 inch width is compatible with standard framing methods in which studs or joists are spaced 16 inches and 24 inches. other lengths and widths of gypsum board are available from the manufacturer on special order.
  19. Gypsum is also an indefinitely recyclable raw material You can always reuse Gypsum because the chemical composition of the raw material in the products remains unchanged the waste of is used to make the same product again.
  20. Properties of gypsum  Gypsum is fire protective Gypsum is non-combustible and able to delay a fire’s spread up to 4 hours.  Gypsum regulates sound. Gypsum walls, ceilings and floors together with insulation materials create quiet zones in the house or business environment.  Gypsum is impact resistant. The Gypsum Industry provides plasterboards, gypsum fibreboards and plaster blocks with a degree of hardness equivalent to a thick wall heavy masonry construction.  Gypsum is easy to install and to dismantle Gypsum is multifaceted, multipurpose, supple and aesthetic
  21. Advantage of gypsum board Gypsum board walls and ceilings have a number of outstanding advantages: Ease of installation Fire resistance Sound isolation Durability Economy Versatility
  22. Edges of gypsum board 1. 2. 3. 4. 5.