Silicate Hydroxide

The significant increase in the use of supplementary cementing materials (such as fly ash and slag) in the last decade has dictated the need for an admixture that can offset the slowed hydration that results when such materials are incorporated in concrete. Strong basic salts such as sodium aluminate, alkali hydroxides, silicates, sulfates and thiosulfates have shown some promise. A number of proprietary admixtures which claim to catalyze the pozzalanic and thereby increase the rate of hydration are now marketed. 

To some extent, the aqueous metal silicate complexes constitute an entire class of placeholders. There is ample evidence that silica forms strong complexes with several metals, but the stoichiometry of such complexes has not yet been established. Different speciation schemes have been proposed to interpret experimental data, for example, 1 2 complexes, chelates, or mixed hydroxide silicate complexes. Despite these ambiguities we decided to include several metal silicate complexes in the data base as guidelines for modellers. Should such complexes turn out to be of crucial importance in particular systems, additional experimental studies would be called for. 

Chemical Composition. With few exceptions, inorganic pigments are oxides, sulfides, oxide hydroxides, silicates, sulfates, or carbonates (see Tables 3 and 4), and normally consist of single-component particles (e.g., red iron oxide, a-Fe203) with well defined crystal structures. However, mixed and substrate pigments consist of nonuniform or multicomponent particles. 

Colloids are always present in natural waters containing the transuranium elements. (Colloids are defined as particles with sizes ranging from 1 to 450 nm. These particles form stable suspensions in natural waters.) Colloids of the transuranium elements can be formed by hydrolysis of transuranium ions, or by the sorption of transuranium elements on the naturally occurring colloids. The naturally occurring colloids include such species as metal hydroxides, silicate polymers, organics (such as humates), and the like. The mobility of the transuranium elements in an aquifer is determined largely by the mobility of its pseudocolloids, that is, those colloidal species formed by the adsorption of the transuranium ions upon the naturally occurring colloids. 

One promising area of investigation is the use of ultrasound to speed up the operating rates of existing aqueous electroplating systems which were not economically viable in the past. These systems can then become feasible and Fitch [102] has described the use of aqueous based compounds such as sodium salts (e.g. hydroxide, silicate, phosphate, carbonate, and borate) as an alternative to the more toxic materials commonly used. These inorganic compounds are inexpensive, readily available, and highly effective in the presence of ultrasound. 

The metals (Li, Na, K) as well as the tungstates and hydroxides (which form during reduction) are liquid at the usual temperatures. No evaporation occurs below 800 °C but, above 800 °C, a partial or total evaporation takes place, depending on the respective element and the nature of the compound (tungstate, hydroxide, silicate, borate, etc.). Lithium as Li3B03, for example, or sodium as silicate are less volatile than LiOH or NaOH. In contrast to Na and K, Li cannot be volatilized due to its high boiling point. 

Total lime is an analytical term for the total CaO plus MgO content of a limestone or lime, expressed in terms of CaO equivalent. It includes the carbonates, oxides, hydroxides, silicates, aluminates, and ferrate. 

H20 Si02 0H- Si02 Viscosity [Hydroxide Silicate > concentration molec. wt. )... 

In nature, manganese can exist as common minerals, snch as carbonates, oxides, hydroxides, silicates, and to a limited extent as snlfides (Table 10.1). Next to iron, manganese is the most abundant element in the earth s crnst and is fonnd in variable concentrations in living organisms, water. 

Groenen, E.J.J., Kortbeek, AG.TG., Mackay, M. and Sudmeijer, O. (1986) Double-ring silicate anions in tetraall lammonium hydroxide/silicate solutions their possible role in the synthesis of silicon rich zeolites . Zeolites 6,403-411. 

Aluminum hydroxide silicate sulfate. See Aluminum hydroxide sulfate Aluminum hydroxide sulfate CAS 53810-32-5... 

Synonyms Aluminum hydroxide silicate sulfate Basic aluminum sulfate Polyaluminum silicate sulfate... 

The alkaline activators include sodium or potassium hydroxide, silicate, and carbonate. The rate of setting and hardening of alkali-activated binders and the quality and quantity of the resulting reaction products depend on a variety of factors, including the quality of the starting aluminosilicate, the quality and amount of alkaline activator, and the temperature of reaction. 

Effect on Membrane Calcium deposits as hydroxide, silicate, aluminate, and other compounds in the cathode layer of the membrane, and causes physical disruption (holes). Current efficiency can decline to as low as 85%. 

Alkalinity sodium hydroxide, silicate Stabilize bleach 0.25-5... 

Sodium hydroxide Potasssium hydroxide Silicates Ethylene glycol Ethanolamine isopropyl alcohol Phosphates... 

The exchangeable Al fraction in soils is not as clearly defined experimentally as are the exchangeable fractions of the alkali and alkaline-earth cations, Ca ", Mg , K " and Na " (Lee et al, 1985). This is because it is in fairly-rapid equilibrium with two other Al sinks, i.e Al ions trapped between the alumino-silicate layers of some clay minerals (the so-called interlayer Al) and the amorphous Al hydroxide/silicate material mentioned earlier. 

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