Caustic alkalinity

Oxidation or "sweetening" is used on gasoline and distillate fractions. A common oxidation process is also a Merox process that uses a solid catalyst bed. Air and a minimum amount of alkaline caustic ("mini-alky" operation) is injected into the hydrocarbon stream. As the hydrocarbon passes through the Merox catalyst bed, sulfur mercaptans are oxidized to disulfide. In the sweetening Merox process, the caustic is not regenerated. The disulfide can remain with the gasoline product, since it does not possess the objectionable odor properties of mercaptans hence, the product has been sweetened. 

Because its outet valence electrons ate at a gteatet distance from its nuclei, potassium is more reactive than sodium or lithium. Even so, potassium and sodium are very similar in their chemical reactions. Due to potassiums high reactivity, it combines with many elements, particularly nonmetals. Like the other alkali metals in group 1, potassium is highly alkaline (caustic) with a relatively high pH value. When given the flame test, it produces a violet color. 

During the Middle Ages and Renaissance, any element that could not be easily recognized by its outward physical properties, that was not considered a metal, and that was not soluble in water was considered an earth element. This classification was a holdover from the ancient Greek concept that all elements fit into one of the three categories of earth, fire, and air. In addition, any substance that acted in ways similar to potash and soda (alkaline caustics) were classed as alkali earth metals. 

Specifically, EOR activity can be classified into three major types (1) chemical, (2) miscible displacement, and (3) thermal. The first category includes the injection of surfactants (micellar), polymers, alkaline (caustic), and carbon dioxide. In miscible displacement, a gas or liquid hydrocarbon is injected into the reservoir where it becomes miscible with the hydrocarbons... 

It occurs in white or grayish, amoxphous masses odorless alkaline caustic almost infusible sp. gr. 2.3. With H,0 it gives off great heat and is converted into the hydrate slacking). In air it becomes air-slacked falling into a white powder, having the oompoaition CaCO CaH,0,. 

Precaution Strongly alkaline caustic material violent reaction with Fj Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of Na O... 

Toxicology LD50 (oral, rat) 1153 mg/kg LDLo (IP, guinea pig) 200 mg/kg poison by ing., IP routes severe eye, skin, mucous membrane irritant ing. causes Gl tract upset experimental reproductive effects TSCA listed Precaution Strongly alkaline caustic material violent reaction with F2... 

Hydrometallurgical concentration processes. Because monazite is a relatively chemically inert mineral, only two hydrometallurgical dissolution processes can be efficiently used for recovering thorium. Actually, the hydrometallurgical processing of monazite ore concentrate is carried out either by concentrated sulfuric acid or by strong alkaline caustic hot digestion. 

During a 4-year time period from 1976 to 1980 in Boston, Massachusetts, USA, 857 inpatients were admitted to a specialized bum center [30]. Of these, 35 (4 %) had chemical injuries. Involved chemicals included acids (hydrochloric, sulfuric, hydrofluoric, chlorosulfonic, trichloroacetic, and undetermined acidic substances) (10 cases) and alkaline caustic substances (lye, cement) (9 cases). The chemical exposures were work related in 51 % of cases, and in 7 cases (20 %), they were due to deliberate chemical assaults. Some patients had relatively immediate copious water washing and some did not. Patients with delayed water decontamination had a fivefold greater incidence of fullthickness chemical skin injuries, but even immediate and copious potable water washing was unable to prevent chemical skin injuries in all cases [30]. 

A study performed in Iowa City, Iowa, USA (a major agricultural area), of patients admitted to a specialized bum center, 94 of a total of 2,762 had chemical skin injuries (3.3 %) [32]. Involved chemicals included anhydrous ammonia (31/94, 34 %), acids (14), alkaline caustic substances (68), organic chemical agents (6), and undetermined chemical agents (5 cases). The majority were occupationally related. There was one fatality and 36/94 patients required skin grafting surgical procedures, some of whom required multiple such procedures. Complications that occurred include wound infections, pneumonitis, cardiac dysrhythmias, and myocardial infarction (overall, 24/94,25.5 %). Sequelae occurred in 27/94 cases (28.7 %). Early and copious potable water decontamination did not prevent some serious chemical skin injuries from develop-ing[32] (see also Sect. 4.4.1.2) (Tables 1.4and 1.5). 

Inhalation, The effects of inhalation exposure to corrosives can vary from severe but reversible irritation of the respiratory system to pulmonary edema, pneumonitis, complete destruction of the respiratory mucosa, or systemic poisoning. Examples 1) Ammonia gas produces a severe irritation of the respiratory tract through alkaline caustic action. 2) Chlorine, phosgene, or nitrogen oxides cause an initial irritation of the respiratory tract, but these chemicals may also eventually produce a delayed or even relapsing pulmonary edema. 3) Ethyleneimine and... 

Toxicology Ing. causes throat Irritation Inh. of high concentrations can cause mild irritation to nasal passages eye contact may result in burns, severe eye Irritation Precaution Wear impervious gloves, chemical goggles incompat. with strong oxidizers, alkaline, caustic materials... 

Usually prepared on the large scale by caustic soda fusion of sodium naphthalene-1-sulphonate, but can also be obtained by high-temperature alkaline digestion of... 

Hydrolysis of Acetanilide. Anilides in general, such as acetanilide and benzanilide (p. 245), may be hydrolysed by caustic alkalis or by acids. Alkaline hydrolysis, however, is usually very slow, and therefore... 

It is frequently advisable in the routine examination of an ester, and before any derivatives are considered, to determine the saponification equivalent of the ester. In order to ensure that complete hydrolysis takes place in a comparatively short time, the quantitative saponi fication is conducted with a standardised alcoholic solution of caustic alkali—preferably potassium hydroxide since the potassium salts of organic acids are usuaUy more soluble than the sodium salts. A knowledge of the b.p. and the saponification equivalent of the unknown ester would provide the basis for a fairly accurate approximation of the size of the ester molecule. It must, however, be borne in mind that certain structures may effect the values of the equivalent thus aliphatic halo genated esters may consume alkali because of hydrolysis of part of the halogen during the determination, nitro esters may be reduced by the alkaline hydrolysis medium, etc. 

Most aromatic acid chlorides impart a strongly acid reaction when shaken with water (compare Section 111,88). All are completely hydrolysed by boiling with solutions of caustic alkalis and yield no product volatile from the alkaline solution (compare Eaters, Sections 111,106 and IV, 183). They may be distinguished from acids by their facile reactions with alcohols (compare Section 111,27), phenols (compare Section IV,114), and amines (compare Sections 111,123 and IV.lOO). 

Aqueous solutions of caustic soda aie highly alkaline. Hence caustic soda is ptimatily used in neutralization reactions to form sodium salts (79). Sodium hydroxide reacts with amphotoric metals (Al, Zn, Sn) and their oxides to form complex anions such as AlO, ZnO. SnO ", and (or H2O with oxides). Reaction of AI2O2 with NaOH is the primary step during the extraction of alumina from bauxite (see Aluminum compounds) ... 

Caustic soda solutions are normally tested for general alkalinity and percentages of NaCl, Na2S04, and NaClO as weU as for Fe and Ni levels. The general methods are outlined in Table 22. Detailed analytical methodologies are available from the major caustic soda suppHers. 

Petroleum and Natural Gas. Over 90% of the 428,000 t of caustic soda used in the petroleum and natural gas industry is used to process oil and gas into marketable products, especially by removing acidic contaminants. The remainder is used primarily to decrease corrosion of drilling equipment and to increase the solubiUty of drilling mud components by maintaining an alkaline pH (6). 

The Huron-Dow Process. The Huron-Dow (H-D) process is a refinement of the cathodic reduction of oxygen in an alkaline electrolyte yielding low strength hydrogen peroxide directiy. Earlier attempts reHed on neutralizing the excess caustic or forming insoluble metal peroxides (92). The two reactions involved are... 

This secondary reaction starts at about 180°C, but the mass must be heated to 350—400°C to bring the reaction to completion and produce a nitrate-free product. The off-gases are extremely corrosive and poisonous, and considerable attention and expense is required for equipment maintenance and caustic-wash absorption towers. Treatment of the alkaline wash Hquor for removal of mercury is required both for economic reasons and to comply with governmental regulations pertaining to mercury ia plant effluents. 

The fine mica fraction is deslimed over 0.875—0.147-mm (80—100-mesh) Trommel screens or hydrocylcones, or is separated with hydrosi2ers. The deslimed pulp (<0.589 mm (—28 mesh)) of mica, feldspar, and quart2 is then fed to a froth flotation circuit where these materials are separated from each other either by floating in an acid circuit with rosin amine and sulfuric acid (2.5—4.0 pH), or an alkaline circuit (7.5—9.0 pH) with tall oil amine, goulac, rosin amine acetate, and caustic soda (see Eig. 2). 

Because of thek flash pokits, nitroparaftins are classified as flammable Hquids under DOT regulations (ha2ard class 3, PG III). Nitromethane and nitroethane tires can be extinguished with water, CO2, foam, or class ABC dry chemical extinguishers. Nitroparaftins should not be exposed to dry caustic soda, lye, or similar alkaline materials. 

Standard 0.25 or 0.50 lb (227 g) tin coated cans are used for packaging Hquid with neutral and mildly alkaline base formulas polypropylene is used for acid—base removers. Steel and polypropylene dmms are used for industrial removers. Viscous removers are packaged in removable top containers. Dry caustic removers are packaged in bag-lined boxes or fiber dmms. 

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