Solid Caustic

Solid Forms and Their Production. There is a relatively small market for solid caustic. Certain applications require the fused material, and in other cases freight savings offset the additional processing cost. We consider three forms of solid here bulk, flaked, and prilled. KOH is seldom formed into prills. 

Bulk solid, usually in drums, is made from molten caustic simply by pouring it into containers and allowing it to cool. This is the cheapest process, giving the least convenient and perhaps most hazardous form of the product. It is often removed from drums by directing a stream of water into the open tops. The drums should then be upended for greater safety. Some types of drum are simply cut away from the block of caustic, leaving a solid mass to be handled or dissolved. 

This apparently simple process requires several tradeoffs and the balancing of 

small particles are more easily cooled but may be flung into contact with the tower walls while still molten  

large particles avoid the above problem and may have better flow properties when dry, but they require more time to cool even as they fall faster and spend less time in the cooling zone  

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CAUSTIC SODA, DRY, SOLID CAUSTIC SODA, SOLUTION CDEC see SULFALLATE... 

Chemical Reactivity - Reactivity with Water A slow, non-hazardous reaction occurs, forming propanolamine Reactivity with Common Materials No reactions Stability During Transport The product is stable if it is kept in contact with solid caustic soda (sodium hydroxide) Neutralizing Agents for Acids and Caustics Dilute with water and rinse with vinegar solution Polymerization This material will polymerize explosively when in contact with any acid Inhibitor of Potymerization Solid sodium hydroxide (caustic soda). 

Dissolve about i gram of an organic base (brucine, strychnine, quinine, c.) in 10 c.c. of a mixture of equal volumes of concentrated hydrochloric acid and water. To the clear hot solution add excess of platinic chloride and let it cool. Yellow microscopic crystals of the chloroplatinate of the base separate. (If the chloroplatinate of the base is very soluble in water, such as aniline, it must be washed with strong hydrochloiic acid, pressed on a porous plate and dried in a vacuum-desiccator over solid caustic potash.)... 

Methylated spirit contains, in addition to ethyl and methyl alcohols, water, fusel-oil, acetaldehyde, and acetone. It may be freed from aldehyde by boiling with a—3 per cent, solid caustic potash on the water-bath with an upright condenser for one hour, or if larger quantities are employed, a tin bottle is preferable, which is heated directly over a small flame (see Fig. 38). It is then distilled with the apparatus shown in Fig. 39. The bottle is here surmounted with a T-piece holding a thermometer. The distillation is stopped when most of the spirit has distilled and the thermometer indicates 80°. A further purification may be effected by adding a little powdered permanganate of potash and by a second distillation, but this is rarely necessary. The same method of purification may be applied to over-proof spirit, which will henceforth be called spirit as distinguished from the purified product or absolute alcohol. 

Dichloroethylene in contact with solid caustic alkalies or their cone, solutions will form chloroacetylene which ignites in air [1], Distillation of ethanol containing 0.25% of the halocarbon with aqueous sodium hydroxide gave a product which ignited in air [2]. 

Ethylenimine , Brochure 125-521-65, Midland (Mich.), Dow Chemical Co., 1965 It is very reactive chemically and subject to aqueous auto-catalysed exothermic polymerisation, which may be violent if uncontrolled by dilution, slow addition or cooling. It is normally stored over solid caustic alkali, to minimise polymerisation catalysed by presence of carbon dioxide. 

In the contact plant for the manufacture of sulphuric acid, sulphuric acid is itself used for drying the air for the oxidation of the sulphur. When drying hydrocarbons such as benzene, it is sometimes convenient to pass the material through a bed of solid caustic soda, although, if the quantity is appreciable, this method is expensive. 

Diazomethane. This formula is designed for immediate use. 10 g of nitrosomethylurea is added (with continued shaking) in small portions to 100 cc of ether and 30 cc of 40% caustic potash, in a wide mouthed flask and cooled to 0°. This must be done very carefully in a fume cupboard. After 10 min, the yellow ethereal extract is separated, and dried for 3 hours with a little solid caustic potash. This ethereal solution of diazomethane should not be kept for more than several days, and for preparative work, it is used in solutions only. 

First, the tar acids were removed from the naphtha fractions of light oils and, in the case of CVR tars, carbolic oil. The oils were then mixed with 25—35% sulfuric acid. After separation of the sulfates, the aqueous solution was diluted with water and the resinous material skimmed off. The diluted sulfate solution was boiled to expel any neutral oils, dried by the addition of solid caustic soda or azeotropically with benzene, and fractionated to yield pyridine, 2-methylpyridine (a-picoline), and a fraction referred to as 90/140 bases, which consisted mainly of 3- and 4-methylpyridines and 2,6-dimethylpyridine (2,6-lutidine). Higher boiling fractions were termed 90/160 and 90/180 bases because 90% of the product distilled at 160 and 180°C, respectively. 

We are told by H. Davy that, in 1790, M. Tondi attempted to obtain the constituent elements of these earths by heating a mixture of the oxide with carbon. In some cases he obtained metallic reguli. H. Davy also pointed out that G. E. Stahl approached very nearly to the discovery of the pure alkalies, for he exposed a mixture of solid caustic potash and iron filings to a long-continued heat, and stated that in this way an intensely caustic alkali—valde causticum—is produced. The oxides were not definitely resolved into their elements until 1807, when H. Davy isolated potassium and sodium by the electrolysis of their hydroxides. 

Toluol.—When tolu balsam is distilled, there passes over a large quantity of benzoic, mixed with a little cinnamic acid, and a yellow liquid, which is a mixture of toluol and benzoic ether. By redistilling this, so as only to collect the portions which pass over hetweas 265° and 285°, a distillate is obtained, which, when deprived of benzole acid by distillation with solid caustic potaaaa, possesses the properties which belong to toluol. 

Vanadium Subnitride, VgN, is described as a black powder which is not attacked by hydrochloric acid or caustic potash solution. It is soluble in concentrated nitric and sulphuric acids, and evolves ammonia on being heated with solid caustic potash. 

Trimethylplatinic iodide, (CH3)3PtI.—Chloroplatinic acid is used in the preparation, and in order that the method may be successful the acid must be pure. It is heated at 200° C. at atmospheric pressure in a distilling flask placed in a metal-bath the water and hydrochloric acid evolved are absorbed by suction through a Woulfe s bottle containing solid caustic potash. After several hours the acid remaining is nearly pure. It is further treated with anhydrous ether until part... 

Special Methods.—With some substances it is difficult to obtain good crystals by the methods already described. A method which frequently gives excellent results consists in dissolving the substance in some solvent, then adding a second solvent miscible with the first, but in which the substance is sparingly soluble. The first solvent is then gradually removed and the substance separates out—usually in the crystalline form. If the first solvent is the more volatile in air, spontaneous evaporation in air may diminish its concentration in the solution. The solution may be placed in a desiccator over some substance which absorbs the first solvent but not the second in this way water may be removed from a water-alcohol solution by solid caustic potash or quicklime. 

Crude ethylidinebisacetoacetic ester as prepared in Preparation 74 is melted on the water bath and poured into 500 c.cs. 20% sulphuric acid in a round-bottomed flask attached to a reflux condenser. A few pieces of porcelain chips are added, and the whole vigorously boiled for 7 hours. It is then steam distilled until the distillate measures about 100 c.cs. The distillate is then set aside in a well-stoppered bottle. The residue is again refluxed for 7 hours and again steam distilled, 100 c.cs. of distillate being again collected. The process is repeated a third time, and then steam is blown into the mixture until no oil, or only a trace, separates from a test portion when treated with solid caustic potash. To the three united... 

Separation.—The condensate is poured into a separating funnel and allowed to stand until separation into two layers is complete. This may be assisted by applying heat or by adding salt. The aniline is then poured off, dried over solid caustic soda and distilled. 

A very convenient method consists in dropping cone, ammonia solution on to solid caustic potash or soda packed in a drying tower or in a flask. If a relatively large quantity of alkali is used the gas evolved is dry. 

It was the practice to neutralize slight acidity in such solvents in a pressure vessel (called a neutralizer) that was filled with solid caustic soda flakes or beads. Such treatment was a common method to improve tainted inventories of solvent intermediates and products. The operating team was pleased to secure the equipment and caustic soda to improve this product. 

The product of dais reaction can be removed as an azeotrope (84.1% amide, 15.9% acetic acid) which boils at 170.8—170.9°C. Acid present in the azeotrope can be removed by the addition of solid caustic soda [1310-73-2] followed by distillation (2). The reaction can also take place in a solution having a DMAC-acetic acid ratio higher than the azeotropic composition, so that an azeotrope does not form For dais purpose, dimethylamine is added in excess of the stoichiometric proportion (3). If a substantial excess of dimethylanoine reacts with acetic acid under conditions of elevated temperature and pressure, a reduced amount of azeotrope is formed Optimum temperatures are between 250 —325°C, and pressures in excess of 6200 kPa (900 psi) are required (4). DAIAC can also be made by the reaction of acetic anhydride [108-24-7] and dimethylamine ... 

Has produced liver and kidney injury in experimental animals. Mutation data reported. Sometimes thought to be nonflammable, however, it is a dangerous fire hazard when exposed to heat or flame. Reaction with solid caustic alkalies or their concentrated solutions produces chloracetylene gas, which ignites spontaneously in air. Reacts violently with N2O4, KOH, Na, NaOH. Moderate explosion hazard in the form of vapor when exposed to flame. Can react vigorously with oxidizing materials. To fight fire, use water spray, foam, CO2, dr) chemical. When heated to decomposition it emits toxic fumes of Cl . See also VINYLIDENE CHLORIDE and CHLORINATED HYDROCARBONS, ALIPHATIC. 

In 50 g/1 solid caustic yields a product that has very good detergency, low foam, and a wetting time (via Draves Cotton Skew Test) of agent 10-13 seconds. 

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