Neutralisation stage

The existing installation will be modified to be used as the neutral leaching and neutralisation stages, with independent circuits for concentrates with high and low silver contents. 

For the manufacturer of 70% AD SLES and 70-75% AD coco-PAS, rheological changes that take place during the neutralisation stage start-up can result in very high apparent viscosities (K is about 100 Ns/m or 100 000 cP) and thus hi pressure drops in the neutralisation loop reactor. This has implications for the mechanical design of pumps, mixers, pipe sizing and equipment lay-out. 

Automatic pH control of the paste from the neutralisation stage works as follows ... 

After cleavage the reaction mass is a mixture of phenol, acetone, and a variety of other products such as cumylphenols, acetophenone, dimethyl-phenylcarbinol, a-methylstyrene, and hydroxyacetone. It may be neutralised with a sodium phenoxide solution (20) or other suitable base or ion-exchange resins. Process water may be added to facilitate removal of any inorganic salts. The product may then go through a separation and a wash stage, or go direcdy to a distillation tower. 

Sheet steel is normally prepared for application of enamel by a sequence of operations including thorough degreasing, acid pickling and neutralisation. A nickel dip stage is often included to deposit a thin, porous layer of nickel applied at about 1 g/m especially when conventional groundcoat is not used (see Section 13.7). 

With a knowledge of the pH at the stoichiometric point and also of the course of the neutralisation curve, it should be an easy matter to select the appropriate indicator for the titration of any diprotic acid for which K1/K2 is at least 104. For many diprotic acids, however, the two dissociation constants are too close together and it is not possible to differentiate between the two stages. If K 2 is not less than about 10 7, all the replaceable hydrogen may be titrated, e.g. sulphuric acid (primary stage — a strong acid), oxalic acid, malonic, succinic, and tartaric acids. 

For the primary stage (phosphoric) V) acid as a monoprotic acid), methyl orange, bromocresol green, or Congo red may be used as indicators. The secondary stage of phosphoric) V) acid is very weak (see acid Ka = 1 x 10 7 in Fig. 10.4) and the only suitable simple indicator is thymolphthalein (see Section 10.14) with phenolphthalein the error may be several per cent. A mixed indicator composed of phenolphthalein (3 parts) and 1-naphtholphthalein (1 part) is very satisfactory for the determination of the end point of phosphoric(V) acid as a diprotic acid (see Section 10.9). The experimental neutralisation curve of 50 mL of 0.1M phosphoric(V) acid with 0.1M potassium hydroxide, determined by potentiometric titration, is shown in Fig. 10.6. 

Mung bean seedlings at different stages of development were treated with 24% (by weight) KOH to extract non-cellulosic polysaccharides as fully as possible. After neutralisation of the extracts, the polysaccharides were isolated by ethanol precipitation, and... 

V. G. Mosienko, Y. I. Petrakov, V. F. Nagomova, and V. N. Nikiforova. Complex additive for plugging solutions—contains modifying reagent in form of waste from production of sebacic acid, from stage of neutralising of sodium salts of fatty acids. Patent RU 2074310-C, 1997. 

Large amounts of residual acid may cause damage to the wool, so that careful neutralisation after baking is an essential and important stage of the process. Carbonised fabrics allowed to accumulate without neutralisation at moderate humidity may suffer considerable damage, so it is essential that neutralisation should take place as soon as possible after carbonising. Neutralisation with ammonia or a mixture of ammonia and ammonium acetate is achieved more rapidly than with sodium carbonate or sodium acetate the ammonia is best used cold [146,286,290]. 

At the final stage, the mitigation system is composed of an isolation system and a system for neutralisation (both with changes to the originally proposed). 

The process comprises the following stages (Fig. 45) the preparation of the reactive mixture hydrolytic condensation the neutralisation and drying of the cocondensation products catalytic regrouping and filtering rectification. 

The production of oligohydridemethylsiloxane comprises three main stages the hydrolytic condensation of methyldichlorosilane the neutralisation of the product of hydrolytic condensation the settling and centrifuging... 

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