Asbestos crudes

Trimethylene Di-iodide. Use 76 g. of trimethylene glycol, 27 - 52 g. of pmified red phosphorus and 254 g. of iodine. Lag the arm C (Fig. Ill, 40, ) with asbestos cloth. Stop the heating immediately all the iodine has been transferred to the fiask. Add water to the reaction mixture, decolourise with a httle sodium bisulphite, filter, separate the crude iodide, wash it twice with water, dry with anhydrous potassium carbonate and distU under reduced pressure. B.p. 88-89°/6 mm. Yield 218 g. (a colourless liquid). 

C. Fumaric acid from furfural. Place in a 1-litre three-necked flask, fitted with a reflux condenser, a mechanical stirrer and a thermometer, 112 5 g. of sodium chlorate, 250 ml. of water and 0 -5 g. of vanadium pentoxide catalyst (1), Set the stirrer in motion, heat the flask on an asbestos-centred wire gauze to 70-75°, and add 4 ml. of 50 g. (43 ml.) of technical furfural. As soon as the vigorous reaction commences (2) bvi not before, add the remainder of the furfural through a dropping funnel, inserted into the top of the condenser by means of a grooved cork, at such a rate that the vigorous reaction is maintained (25-30 minutes). Then heat the reaction mixture at 70-75° for 5-6 hours (3) and allow to stand overnight at the laboratory temperature. Filter the crystalline fumaric acid with suction, and wash it with a little cold water (4). Recrystallise the crude fumaric acid from about 300 ml. of iif-hydrochloric acid, and dry the crystals (26 g.) at 100°. The m.p. in a sealed capillary tube is 282-284°. A further recrystaUisation raises the m.p. to 286-287°. 

Carcinogens Cancer-producing agents Skin Respiratory Bladder/urinary tract Liver Nasal Bone marrow Coal tar pitch dust crude anthracene dust mineral oil mist arsenic. Asbestos polycyclic aromatic hydrocarbons nickel ore arsenic bis-(chloromethyl) ether mustard gas. p-naphthylamine benzidine 4-am i nodi pheny lam ine. Vinyl chloride monomer. Mustard gas nickel ore. Benzene. 

Roh-alkohol, m. crude (or raw) alcohoL -analyse, /. rough or approximate analysis, -antimon, n. crude antimony, -arbeit, /, (Metal.) ore smelting, -asbest, m. crude asbestos. -aufbereitung, /. preliminary preparation, -benzol, n. crude benzene, benzol (or benzole), -blei, n. crude lead, -blende, /. (Mining) crude blende, -block,... 

The oxidation of the crude /3-chloropropionaldehyde is carried out in a 200-cc. flask fitted with a cork stopper held by a clamp about 2 cm. %bove the opening of the neck. The stopper carries a mechanical stirrer, a separatory funnel, a thermometer and a glass delivery tube about 10 mm. in diameter which is connected to a water pump. The space between the stopper and the flask is closed by winding a strip of asbestos paper around it (Note 3). 

US military requirements for crude asbestos are given in specification MIL-A-13651 and for asbestos sheet, compressed, MIL-A-7021A... 

A somewhat crude though convenient classification can be made on the basis of the principal ingredients, thus. (1) Portland cement, (2> high alumina cemenl. (3) sodium silicate. (4 magnesium oxychloride plus copper powder, (5) litharge or red lead plus glycerol. (6) rubber latex, and (7) synthetic resins. Supplementary materials to be considered are asbestos, white lead, plaster of Paris, sulfur, graphile, sand, pilch, tar, rosin, and boiled linseed oil. 

Preparation of Tetryl. Twenty grams of dimethylaniline is dissolved in 240 grams of concentrated sulfuric acid (d. 1.84), the temperature being kept below 25°, and the solution is allowed to run from a separatory funnel drop by drop into 160 grams of 80 per cent nitric acid (d. 1.46), previously warmed to 55° or 60°, while this is stirred continuously and kept at a temperature between 65° and 70°. The addition requires about an hour. After all has been added, the stirring is continued while the temperature of the mixture is maintained at 65° to 70°. The material is allowed to cool the solid matter is collected on an asbestos filter, washed with water, and boiled for an hour with 240 cc. of water while further water is added from time to time to replace that which boils away. The crude tetryl is filtered off, ground under water to pass a 150-mesh sieve, and boiled twice for 4 hours each time with 12 times its weight of water. The solid is dried and treated with benzene sufficient to dissolve all readily soluble material. The solution is filtered and allowed to evaporate spontaneously, and the residue is recrystal-... 

In 1984, the NRC (1984) recommended that a conversion be used to measure asbestos fibers. It was suggested that crude approximations could be achieved by assuming that 1 PCM f/mL is equal to 60 TEM f/mL. Both 1 PCM f/mL and 60 TEM f/mL are approximately equal to a mass concentration of 30 pg/m. Since the health effects data regarding inhalation exposure to asbestos are usually expressed in terms of PCM f/mL, ambient air data reported in units of ng/m or TEM 17mL are converted to units of PCM f/mL using the factors suggested by NRC (1984). 

A Crude asbestos 1 hand selected, unshredded contains staple fibers > 1.90 cm and longer... 

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