Acid solutions, neutralization with calcium carbonate

SPILL CLEAN-UP ventilate area of spill shovel spilled material into suitable dry containers and place in a secured sanitary landfill use water spray to control dust wash liquid spills with buffer or mild acid solution neutralize with natural carbon dioxide and precipitate calcium carbonate. 

Either the Mohr titration or the adsorption indicator method may be used for the determination of chlorides in neutral solution by titration with standard 0.1M silver nitrate. If the solution is acid, neutralisation may be effected with chloride-free calcium carbonate, sodium tetraborate, or sodium hydrogencarbonate. Mineral acid may also be removed by neutralising most ofthe acid with ammonia solution and then adding an excess of ammonium acetate. Titration of the neutral solution, prepared with calcium carbonate, by the adsorption indicator method is rendered easier by the addition of 5 mL of 2 per cent dextrin solution this offsets the coagulating effect of the calcium ion. If the solution is basic, it may be neutralised with chloride-free nitric acid, using phenolphthalein as indicator. 

Common pollutants in a titanium dioxide plant include heavy metals, titanium dioxide, sulfur trioxide, sulfur dioxide, sodium sulfate, sulfuric acid, and unreacted iron. Most of the metals are removed by alkaline precipitation as metallic hydroxides, carbonates, and sulfides. The resulting solution is subjected to flotation, settling, filtration, and centrifugation to treat the wastewater to acceptable standards. In the sulfate process, the wastewater is sent to the treatment pond, where most of the heavy metals are precipitated. The precipitate is washed and filtered to produce pure gypsum crystals. All other streams of wastewater are treated in similar ponds with calcium sulfate before being neutralized with calcium carbonate in a reactor. The effluent from the reactor is sent to clarifiers and the solid in the underflow is filtered and concentrated. The clarifier overflow is mixed with other process wastewaters and is then neutralized before discharge. 

Piitz [11] obtained a patent for the preparation of dinitroglycerine relatively free from the trinitrate by dissolving 1 part of glycerine in 3.3 parts of nitric acid (sp. gr. 1.5) below 15°C. The solution was diluted with 1 part of water and neutralized with calcium carbonate. The product was separated as an oil and a small quantity was extracted with ether from the aqueous solution. 

The amine (0.1 mole) is diazotized in hydrochloric or sulfuric acid solution by sodium nitrite (7 g), the volume of solution being kept as small as possible. The diazonium salt solution is neutralized with calcium carbonate and filtered, and trisodium hexanitritocobaltate (15 g) is stirred into the filtrate, whereupon the trisdiazonium salt usually separates as a solid. For conversion into the nitro compound this salt (10 g), finely powdered, is added in portions, at room temparature, with good stirring, to a solution of sodium nitrite (lOg) and copper sulfate (10 g) in water (60 ml) in which copper(i) oxide (4 g) is suspended. When evolution of nitrogen ceases the nitro compound is isolated either by extraction with a solvent, e.g., chloroform, or by basification of the solution and steam-distillation.172... 

The original product sold in the United States contains -30% lithium hypochlorite (35% available chlorine), 34% sodium chloride, 20% of potassium and sodium sulfates, 3% lithium chloride, 3% lithium chlorate, 2% lithium hydroxide, 1% lithium carbonate, and the balance is water. It is made from lithium sulfate that is extracted into water from a lithium aluminum silicate ore after it is treated with sulfuric acid. The resulting solution also contains sodium and potassium sulfates. It is neutralized with calcium carbonate to pH 6, treated to remove calcium and magnesium, filtered, and concentrated. Sodium hydroxide is added to convert lithium carbonate to lithium hydroxide. The solution is cooled to 0°C and the resulting sodium carbonate decahydrate crystals are removed by filtration. Slightly more sodium hydroxide than the molar equivalent of lithium hydroxide is then... 

Toward alkali, the lactones are less reactive than the acids. A solution of free acid can be neutralized with calcium carbonate or barium benzoate. Sodium carbonate reacts with the 6-lactones and an excess of sodium hydroxide with the 7-lactones. 

About 250 ml of a reaction mixture obtained by the electrolytic reduction of nitrobenzene in sulfuric acid solution and containing about 23 grams of p-aminophenol by assay is neutralized while at a temperature of 60° to 65°C, to a pH of 4.5 with calcium carbonate. The calcium sulfate precipitate which forms is filtered off, the precipitate washed with hot water at about 65°C and the filtrate and wash water then combined. The solution is then extracted twice with 25 ml portions of benzene and the aqueous phase is treated with 0.5 part by weight, for each part of p-aminophenol present, of activated carbon and the latter filtered off. The activated carbon is regenerated by treatment with hot dilute caustic followed by a hot dilute acid wash, and reused a minimum of three times. 

Pentaerythritol is made by mixing formaldehyde with calcium hydroxide in an aqueous solution held at 65-70 °C. Nitration of pentaerythritol can be achieved by adding it to concentrated nitric acid at 25-30 °C to form PETN. The crude PETN is removed by filtration, washed with water, neutralized with sodium carbonate solution and recrystallized from acetone. This manufacturing process for PETN results in 95% yield with negligible by-products. The process is summarized in Reaction 7.9 (overleaf). 

Oxo-2,3-dihydrobcnzotellurophene A solution of 0.18 g (0.68 mmol) of 3-chlorobenzotellurophene in 25 ml of trifluoroacetic acid is heated under reflux for 2.5 h, cooled to 20°, and poured into 100 ml of water. 100 ml of diethyl ether are added, the aqueous phase is neutralized with sodium carbonate, and the organic phase is separated, dried with anhydrous calcium chloride, filtered, and evaporated. The residue is recrystallized from cyclohexane yield 0.14 g (83%) m.p. 107°. 

Add enough analytical grade Dowex 50X8 cation exchange resin, 20-50 mesh, in the hydrogen form, to the solution to make it at least 0.05 M in acid. Filter with suction through a coarse polyethylene or Teflon filter and wash the resin. Neutralize the filtrate with calcium carbonate and concentrate to ca. 400 ml., either in a rotary evaporator or in a Teflon beaker under a heat lamp. 

In soils, F can be found in four major fractions (1) dissolved in soil solution (2) sorbed to Al, Fe, and Mn oxides and hydroxides and carbonates (3) solid phases, such as fluorite and fluorophlogopite and (4) associated with organic compounds. The solubility of F in soil solution is variable and is affected by pH, speciation, adsorption and desorption reactions, and dissolution and precipitation reactions (Luther et al., 1996). Acidic conditions and low calcium carbonate content are favorable to F solubility and can therefore enhance both root uptake (Weinstein and Alscher-Herman, 1982) and migration to surface and ground water (Smith, 1983). These conditions can lead to human, plant, and animal health issues. Soils that do contain appreciable amounts of calcium carbonate and are neutral to slightly alkaline conditions can fix F as insoluble calcium fluoride (CaF2), and reduce its bioavailability and mobility (Kubota et al., 1982 Tracy et al., 1984 Reddy et al., 1993 Poulsen and Dudas, 1998). 

It is relatively simple to determine the extent to which a sulfonation reaction has proceeded. The reaction mixture is neutralized with barium carbonate and treated with enough soda to form the sodium siplt. The number of sulfo groups present can be calculated from the amount of soda used up. One sulfo group requires 53 grams of NaaCOs. Calcium carbonate cannot be used for this purpose since calcium sulfate is soluble in solutions of naphthalenesulfonic acids. 

Figure 10.8 Lumped-process distribution coefficients (/T/s) for some elements measured during laboratory neutralization of acid solutions with calcium carbonate (Taylor 1979). These values represent the combined effects of element removals by adsorption, coprecipitation, and/or precipitation onto and in freshly precipitated Fe(IlI), Al, and Mn(IV) oxy-hydroxides and hydroxysutfates. As such they are system specific and cannot be assumed to apply to other systems under different conditions or having different compositions.

Hexanone from 1-hexyne A mixture of 1 g of mercury(n) sulfate, 1 g of concentrated sulfuric acid, and 150 g of 70% methanol (or 150 g of 70% acetone or 50 g of 60% acetic acid) is warmed to 60° in a 500-ml three-necked flask fitted with a stirrer, dropping funnel, and reflux condenser. 1-Hexyne (41.0 g, 0.5 mole) is dropped in, with stirring, within 1 h. The mixture is stirred for a further 3 h at the temperature stated, then cooled, and worked up. The methanol (or acetone) is distilled off and the 2-hexanone is salted out from the residue by solid sodium chloride. The ketone layer is separated, washed, neutralized, dried over calcium chloride, and distilled, giving 78.8 % of 2-hexanone, b.p. 120°. When acetic acid has been used as solvent, it is neutralized with sodium carbonate solution before working up as above. 

Isolation of the sulfonic acids as salts is usually carried out in one of two ways. In one the sulfonation mixture is taken up in water, neutralized with slaked lime, and filtered from the precipitated calcium sulfate, whereafter the filtrate, which contains the calcium salt of the sulfonic acid, is treated with sodium carbonate which converts the calcium into the sodium salt after filtration from calcium carbonate the solution is concentrated until crystallization occurs or, if necessary, evaporated to dryness. This procedure, termed chalking in industry, can be applied to all sulfonic acids except for the few cases such as l-amino-4-hydroxynaphthalene-2-sulfonic acid that give sparingly soluble calcium salts however, it is inconvenient because of the large volumes of liquid that must later be evaporated to avoid this precipitation of... 

Citric acid occurs widely distributed in nature in many fruits. It is present in raspberries, gooseberries, currants, and other acidulous fruits. It is usually obtained from unripe lemons, the juice of which contains about six per cent of the free acid. In isolating the acid, the juice is neutralized at the ordinary tem-perture with calcium carbonate, and filtered. Tricalcium citrate dissolves readily in cold water, but is difficultly soluble in hot water. As a consequence, when the solution of the citrate obtained from the lemon juice is boiled, the calcium salt of the acid precipitates. This is separated and treated with an equivalent quantity of sulphuric acid after the removal of calcium sulphate, citric acid is obtained by evaporation of the solution to crystallization. Citric acid is formed as the result of the fermentation of glucose by citromycetes pfefferianus. It is prepared on the technical scale in this way. 

In the second method, dilute mixed acid, for example 9 % water mixed acid, is used in the nitration to prepare glycerine dinitrate. After dilution by water, glycerine dinitrate is separated. This is a simple but uneconomical method. The third method was developed by DuPont based on ammonium method [10]. Ammonium is used to neutralize the dilute nitric acid solution to form recoverable ammonium nitrate solution. For glycerine dinitrate without any trinitro esters, one unit of glycerine is dissolved into 3.3 units of nitric acid with the density of 1.5 at 15 °C. The solution will be diluted by one unit of water and neutralized by calcium carbonate. The oily product will be separated out. The small amount of product in water solution will be extracted by ethers. 

Sodium phosphate is prepared from the mineral phosphorite which is a tribasic calcium phosphate. The phosphatic material is digested with sulfuric acid, the mixture is then leached with hot water, neutralized with sodium carbonate, and the sodium phosphate is crystallized from the filtrate. It is the active ingredient in Effervescent Sodium Phosphate, one of the most pleasant of the saline laxatives. It is also used in the preparation of Sodium Phosphate Oral Solution. This solution, which corresponds to 0.75g of the official hydrated salt in each ml. provides an easy form for the administration of a saline laxative and antihypercalcemic (Gennaro, 1990). 

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