Calcined sodium carbonate

The manufacture of a related compound is first described. 28.1 parts of p-chloro-benzhy-dryl bromide are heated to boiling, under reflux and with stirring, with 50 parts of ethylene chlorohydrin and 5.3 parts of calcined sodium carbonate. The reaction product is extracted with ether and the ethereal solution washed with water and dilute hydrochloric acid. The residue from the solution in ether boils at 134° to 137°C under 0.2 mm pressure and is p-chloro-benzhydryl-(/3-chloroethyl) ether. 

Fig. 3.1-2. Production of calcined sodium carbonate from trona by the monohydratc process, a) trona storage b) pulverizer c) sieve d) rotary tube furnace e) dissolution unit f) classifier g) concentrator h) filter press i) activated charcoal filter j) vacuum crystallizer k) cyclone 1) centrifuge m) dryer n) cooler o) classifier p) product stock...

Manufacture In the Solvay process sodium hydrogen carbonate is produced as an intermediate. Due to the high purity requirements of sodium hydrogen carbonate, it cannot, however, be obtained therefrom. It is produced by reacting filtered solutions of calcined sodium carbonate with pure carbon dioxide with cooling ... 

The preparation of pastes is determined by the intended forming process. Castable pastes with a water content of 30 to 35% are stabilized by adding flocculants. Clay-containing slips also contain 0.2 to 0.4% by weight of water glass and other sodium silicates or calcined sodium carbonate, as additives. 

Chloroethyl isothiocyanate 811 2-Chloroethylammonium chloride (50 g), dissolved in water (100 ml), and chloroform (200 ml) are stirred together and cooled in ice while a concentrated aqueous solution of calcined sodium carbonate (130 g) and a solution of thio-phosgene (50 g) in chloroform (50 ml) are dropped in simultaneously the solution must remain alkaline throughout this addition. After a further 0.5 hour s stirring, the chloroform layer is separated, dried over sodium sulfate, and fractionated. The product boils at 80°/13 mm. 

Synonyms Bisodium carbonate Calcined soda Carbonic acid disodium salt Crystol carbonate Disodium carbonate Natron Sal soda Soda ash Soda calcined Sodium carbonate (2 1)... 

Sodium carbonate monohydrate crystals from the crystallizers are concentrated in hydroclones and dewatered on centrifuges to between 2 and 6% free moisture. This centrifuge cake is sent to dryers where the product is calcined 150°C to anhydrous soda ash, screened, and readied for shipment. Soda ash from this process typically has a bulk density between 0.99—1.04 g/mL with an average particle size of about 250 p.m. 

Lime Soda. Process. Lime (CaO) reacts with a dilute (10—14%), hot (100°C) soda ash solution in a series of agitated tanks producing caustic and calcium carbonate. Although dilute alkaH solutions increase the conversion, the reaction does not go to completion and, in practice, only about 90% of the stoichiometric amount of lime is added. In this manner the lime is all converted to calcium carbonate and about 10% of the feed alkaH remains. The resulting slurry is sent to a clarifier where the calcium carbonate is removed, then washed to recover the residual alkaH. The clean calcium carbonate is then calcined to lime and recycled while the dilute caustic—soda ash solution is sent to evaporators and concentrated. The concentration process forces precipitation of the residual sodium carbonate from the caustic solution the ash is then removed by centrifugation and recycled. Caustic soda made by this process is comparable to the current electrolytic diaphragm ceU product. 

North American Chemical Co. produces borax pentahydrate and decahydrate from Seades Lake brines in both Trona and West End, California (see Chemicals frombrines). The 88 km dry lake consists of two brine layers, the analyses of which are given in Table 11. Two distinct procedures are used for the processing of upper and lower lake brines. Borax is produced in Trona from upper lake brines by an evaporative procedure involving the crystallization of potash and several other salts prior to borax crystallization as the pentahydrate (104). A carbonation process is used in West End, California to derive borate values from lower lake brines (105). Raw lower stmcture brine is carbonated to produce sodium bicarbonate, which is calcined and recrystallized as sodium carbonate monohydrate. The borate-rich filtrate is neutralized with lake brine and refrigerated to crystallize borax. 

In this system, the least soluble component is sodium bicarbonate, so this crystallizes out. On calcination it yields sodium carbonate and the carbon dioxide is recycled. The ammonia is recovered by adding calcium hydroxide, producing calcium chloride waste and liberating the... 

All the silica present in the bauxite was converted to insoluble sodium aluminosilicate, which represented a loss of sodium and aluminum. The aluminum hydroxide was calcined to the oxide, and the sodium carbonate solution was concentrated for re-use. The process was developed by H. E. St-Claire Deville in the 1860s the carbon dioxide stage had been invented earlier by H. L. Le Chatelier. It was superseded by the Bayer process. 

In the second stage, the black ash process, the sodium sulfate was reduced to sodium sulfide and then converted to sodium carbonate by calcining with limestone and coal in a rotating kiln known as a black ash furnace or revolver ... 

Seailles-Dyckerhoff A process for extracting aluminum from clays and other aluminous minerals rich in silica. The ore is calcined with limestone in a rotary kiln. The product is leached with aqueous sodium carbonate, yielding sodium aluminate solution, from which alumina is precipitated by carbon dioxide. Invented by J. C. Seailles and W. R. G. Dyckerhoff in 1938 piloted in Tennessee in 1942, South Carolina in 1945, and Germany during World War II. See also Pedersen. 

Andreeva and coworkers518 improved on the preparation of Au/a-Fe203 by using a deposition-precipitation method. The preparation involved deposition of Au hydroxide with a solution of sodium carbonate at 60 °C and pH = 8.0 on a fresh precipitate of iron hydroxide. The precipitate was aged for 1 hour at 60 °C, filtered, washed, dried under vacuum at 80 °C, and calcined in air at 400 °C for 2 hours. A comparison of properties and activities is provided in Table 122. The iron oxide crystallites were about 10 nm in both samples investigated. 

Anionic surfactants are present in surface water, resulting in serious environmental pollution. Therefore, adsorption of surfactants, such as sodium dodecylsulfate [155,156], on Mg/Al LDHs has received considerable attention. Ulibarri et al. also published the results of sorption of an anionic surfactant (sodium dodecylbenzenesulfonate) from water by LDHs and calcined samples (773 K), focusing both on their potential application as a sorbent and on the possibility of their recycling [154,157]. They found that anionic exchange was complete when the interlayer anion in the LDH precursor was Cl", reaching 100 % of AEG, and calcined LDH-carbonates were better adsorbents than those derived from LDH-chloride samples, however. It was also claimed that an increase in the crystallinity of the LDH samples probably leads to better ordered calcined mixed oxides, facilitating reconstruction of the layers and enlarging the absorption capacity. 

Catalysts A, prepared from aluminum isopropoxide and calcined at 700° for 4 hours A—Na, contained 1 % by weight of sodium by impregnation with sodium carbonate A—H, purchased from Harshaw Chemical Company it contained 0.35% of sodium. HLSV = hourly liquid space velocity, grams of alcohol per gram of catalyst per hour. 

A—Alumina made from aluminum isopropoxide and calcined at 700° for 4 hours. B—Alumina A impregnated with sodium carbonate contained 1% Na ". 

The Solvay process involves a series of partial reactions. The first step is calcination of calcium carbonate to form lime and CO2. Lime is converted to calcium hydroxide. The most crucial step of the process involves reacting brine solution with carbon dioxide and ammonia to produce sodium bicarbonate and ammonium chloride. Sodium bicarbonate converts to sodium carbonate. The calcium hydroxide and ammonium chloride react to form calcium chloride as the by-product. The partial reactions are shown below ... 

Vanadium pentoxide is an intermediate in recovering vanadium from minerals (See Vanadium). Sodium polyvanadate, obtained as a red cake in one of the steps in extracting vanadium from its ores is calcined at 700°C in air to form a melt of vanadium pentoxide. Pentoxide is prepared in purified form by dissolving red cake in sodium carbonate solution followed by addition of an aqueous solution of ammonia and ammonium chloride. Ammonium metavanadate is precipitated which on decomposition at 320 to 430°C forms vanadium pentoxide. 

As evaporation proceeded, sodium chloride began to precipitate and later potassium chloride and potassium sulfate. The mother liquor then contained the iodides of sodium and postassium, part of the sodium chloride, sodium sulfate, sodium carbonate, cyanides, polysulfides, and some sulfites and hyposulfites resulting from the reduction of sulfates during calcination. 

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