Lab Scale Preparation of Gypsum Wallboard

Lab Scale Preparation of Gypsum WallboardSTATEMENT OF THE fuss AND SIGNIFICANCE OF PROPOSED RESEARCH (State succinctly the line of work which is to be addressed. Clearly outline the importance of the problem, the originality of the approach and the contact it may have on the field if successful. Give an overview of the broader significance as well as the contiguous impact of this research.)The main purpose of this research is to create a gypsum wallboard with enhanced burn loathly property. Gypsum owns a property of combined piddle content, is a noncombustible and acts as effective lift proofing material. When warming from can comes in contact with a plaster wall (or gypsum wallboard), it begins to lose combined piss as steam thus making the hemihydrate organise of gypsum (stucco) rehydrated and it retrogrades back to dihydrate. Wide range requirements such as harass patient of, increase moisture resistant can be achieved by the use of different calcining methods and a dditives. The wide pertinency of gypsum is in construction. It is also used in the chemical industriesIn producing the fire resistant gypsum wallboards, the various properties of GWB deal thermal, physical, chemical and mechanical characteristics are to be studied which plays a major role in unconditional the scatter of fire in buildings. Gypsum wallboard consists mainly of gypsum i.e. calcium convert dihydrate, CaSO4.2H2O. Calcium sulfate in nature is mostly available in two melodys Calcium sulfate dihydrate is common landly referred as gypsum, which is integrity of the oldest construction materials. It naturally occurs in sedimentary deposits from ancient sea beds. The most distinguishing feature of Gypsum is that it is moderately dissolvable in pissing at room temperature and exhibits a special feature of retrograde solubility i.e. gypsum becomes less(prenominal) soluble at elevated temperatures. Another form of calcium sulfate is the calcium sulfate anhydrite. At a tem perature of 58 C Gypsum and Anhydrite coexist, also the anhydrite exhibits the strong retrograde property but it does not revert back to gypsum as its solubility decreases with increasing temperature. Gypsum wallboard is used to make interior walls and ceilings in residential and commercial applications that often require specific fire rated assemblies.Various types of gypsum wallboard are manufactured, with the most common variety and specialized varieties such as fire resistant, body of pissing resistant, and plaster lath. Combination of beta hemihydrates stucco, water and other additives form slurry which is used in the manufacture of the gypsum wallboard. Additives such as asphalt emulsion, vermiculite, chopped fiber ice rink and paper fiber impart to the wallboard characteristics such as water resistance, fire resistance and strength.The fire resistance property is mainly attributed to the absorption of energy related with the loss of hydrate water waiver from the dihydrate (CaSo4.2H2O) and from the hemihydrates to the anhydrous form (CaSo4). Impinging heat of gypsum wallboards initially operates to reverse the hydration reaction resulting in controlling the spread of fire and penetration of flame through set gypsum grammatical constructions. Fire resistance can be achieved by victimisation appropriate additives such as fiber, glass textile fibers, vermiculite, which expands when heated, which acts against the gypsum shrinkage.Because of its worldwide occurrence and huge potential reserves, however its uses are not considered basic to survival in a national emergency, gypsum is not considered a strategic mineral. This has permitted natural economic factors to prevail in the development of the mineral worldwide, which overall is a levelheaded situation that should continue to prevail.PLAN OF PROCEDURE (Outline the initial approach to the problem and its feasibility. Point out advance(a) features, relate it to previous work including pertinent refe rences, and indicate how this plan may contribute to the solution of the broader problem proposed.)Gypsum manufacturing action consists of three main mistreats (1) rock preparation, (2) calcining and (3) formulating and manufacturing. Though we start with buying the gypsum material from matchless of the providers so the next important step ahead is the calcination process. Gypsum is usually referred to be CaSO4.2H2O. Calcium sulfate dIiydrate undergoes calcination to form hemihydrate (CaSO41/2H2O) or anhydrous form (CaSO4). Initially the calcination process was achieved by heating the raw gypsum material in an open environment, later on with the development in science calcination was achieved by heating the gypsum material in a kiln. Kinetic studies of calcination process plays an important role in determining the gypsum harvest parameters. We are interest in knowing the age, temperature and rate at which the calcination process can be achieved. Initially a low-pitched amount of the gypsum material is taken and X- Ray diffraction studies are conducted on it to know its composition i.e. CaSO4.2H2O or CaSO41/2 H2O or CaSO4 .Later after determining the form of gypsum material, thermogravimetric studies (used for the determination of weight change at different temperatures and time) are conducted on the CaSO4.2H2O to coif the temperature and time required to convert from dihydrate form to hemihydrate and anhydrite form. Again the view ased product is first subjected to XRD and SEM studies to investigate the state of gypsum i.e. dihydrate, hemihydrate or anhydrous form. This can be studied by interpreting the obtained results with the earlier established results. Later gypsum powder is subjected to different temperatures at different time intervals to determine the time and temperature required for the calcination process to finish by using Thermogravimetric Analysis Instrument also first derivative Scanning Calorimetry (which determines the melting and boiling temperatures) studies are also conducted to know the melting temperatures of the product Until now the calcination process is studied by using a very small amount of the sample in a science laboratory environment, the obtained results from these experiments is used to correlate with the calcination process which is done in impetuous air oven by using a large amount of samples. The temperature obtained from the thermogravimetric studies is used as basis for the calcination process in hot air oven. These studies are done to know the reproducibility for large scale leaf samples. This encompasses the first step in our research. The importance of these kinetic studies related to calcination is very useful to determine the conditions for achieving the hemi hydride from calcium sulfate which undergoes rehydration process i.e is extension of water molecules to the hemi hydride form to form the gypsum wallboard.Calcium sulfate hemihydrate (CaSO41/2H2O) or Calcium sulfate anhydrit e (CaSO4) undergoes rehydration in the strawman of water. Rehydration plays an important role as it allows to add the additives such as glass material, vermiculite etc. to the slurry which is referred as stucco. chemically stucco is referred as the hemihydrate form of CaSO4. These additives are added to increase the fire resistant property in admittance to the strength of the wallboards. The kinetic studies related to the rehydration process are studied similar to the calcination step. These kinetic studies gives us orbit for better understanding the process of gypsum wallboard. i.e the amount of water required for rehydration and also the amount of additives that can be added to the gypsum mixture to proceed the chemical stability of the gypsum composition required for the wallboard manufacturing. Similar to the first step this step is studied for the time, temperature and rate of reaction in the open environment and later in the laboratory environment by using kettle. In the k ettle the hemihydrate and hydride forms of calcium are reacted with the water and the obtained product is subjected to the XRD and SEM studies to determine the state of product. This is the second step in our research.The final step in our research is the lab scale preparation of gypsum wallboard which involves the dihydrate form of calcium sulfate react with the sufficient amount of water to form slurry. Theoretically close 18.6 parts of water is required to react with the 100 parts of gypsum but to stick a slurry, otiose of water (about 80 to 85 parts) is reacted with 100 parts of gypsum. In this step water along with 10-30 wt. % of stiffen such as corn starch is added to obtain milk of starch. Next about 0.1 -1.5 wt.% of amolytic enzyme such as amylase based on the starch is added and heated to the decomposition point of the starch with stirring. later on the heating is stopped enzyme deactivating agent based on the starch is added in the range of 0.8 to 1.0 wt. % and mixed with water to obtain a starch paste. To the prepared starch material the calcination product is added along with water and vermiculite, glass materials which improve the fire resistance property of the gypsum wallboard. This mixture is agitated in slow motion to obtain a slurry. This slurry form of gypsum is poured into a paper sheets such as paper boards. The edges of the paper is folded upwards to retain the slurry form of gypsum. The other end of the product is covered with some other paper material which helps to retain the structure of the gypsum board. This mixture is subjected to heating by using hot air press which is useful to remove the excess water and to obtain a specific structure of the gypsum board. This process is continued until all the excess water is removed. It is dried in the temperature range of 50 C-200 C.Starch paste such as denatured starch and dextrin is used as an auxiliary adhesive to prevent calcination of the vitreous silica of gypsum dihydrate and d ehydrated to give a gypsum hemihydrate in drying at utmost temperatures. Also to prevent separation of the gypsum core member from both paper board, circle modifier are added to the raw material of the gypsum core member. It is effective that starch paste along with water in the gypsum core member and both paper boards migrate during drying at high temperatures, and cover the crystal of gypsum dihydrate due to water retention capability of the starch paste which developed into the fiber of the paper boards so as to prevent the calcination and dehydration of the crystals. The obtained wallboard is subjected to different analytical techniques such as Thermogravimetric analysis, Thermomechanical analysis, XRD, SEM and differential gear scanning calorimetry as discussed in the calcination and rehydration step.BUDGET AND BUDGET JUSTIFICATION LAB SCALE PREPARATION OF GYPSUM wallboardMaterials and suppliesA minimum of 50 pounds of raw gypsum is required to make the gypsum wallboard and test its fire resistant property by adding the additives such as starch, dextrose, glass fibers. Initially a wallboard is do without adding each additives and for that about 5 pounds of the powder is used and tested for its properties. Similarly by adding the additives wallboard are made and tested for its properties. If the properties observed are similar to the commonplace fire resistant properties, variations in the additives is done and another wallboard is made to test for its fire resistant property. 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