Bentonites, definition

CAS 68953-58-2 EINECS/ELINCS 273-219-4 Synonyms Ditallow dimethylammonium aluminum silicate Quaternary ammonium compds., bis (hydrogenated tallow alkyl) dimethyl, chlorides, reaction prods, with bentonite Definition Reaction prod, of quaternium-18 and bentonite Toxicoiogy TSCA listed... 

BENTONITE. The term applied to alteied fine-grained volcanic ashes which have been blown considerable distance from their origin and deposited m marine waters. The resulting material is usually a white, but sometimes a colored, clay-like sediment which may contain bits of volcanic glass but is composed mainly of colloidal silica which will absorb large quantities of water. Since bentonites are wind-blown deposits they are useful as definite datum planes in stratigraphy, especially in helping to determine the contemporaneity of the different facies of marine sediments. 

UPC, 2000, Task definition DECOVALEX III, Task 1 Modelling of FEBEX in-situ test. Part B Thermo-hydro-mechanical analysis of the bentonite behaviour. Polytechnical University of Catalonia, Barcelona, Spain. 

In this paper, we provided the rationale and definition of a benchmark test called BMTl to look at the implications of THM couplings on safety parameters in the near field of a hypothetical repository. This hypothetical repository possesses composite features since it is based on a Japanese design, with a Japanese bentonite used as buffer material and the heat output characteristics of Japanese spent fuel. However, the permeability and strength characteristics of the rock mass are based on typical properties of granites of the Canadian Shield. 

Swelling of stratified mineral. Polar adsorbate such as water absorbing at rather definite pressures. Water on and in Wyoming bentonite [39]... 

Soap clay Southern bentonite Wilkinite Definition Native hydrated colloidal aluminum silicate clay Formula AljOj 4Si02 nHiO... 

Definition Reaction prod, of bentonite, quaternium-18, and benzalkonium chloride... 

Definition A prep, of bentonite with purified water Uses Suspending agent, thickener for pharmaceutical topicals... 

Bentonite ben-t n- It (1898) n. Very finegrained clay (a mixture and not a definite mineral type) derived from volcanic ash and consisting largely of montmorillonite mineral. Two classes of Bentonite are recognized (1) sodium bentonite, which is a swelling type in water and (2) calcium bentonite or subbentonite, which exhibits httle swelling in water. 

The materials that fulfil all the conditions stated in this definition are kaolin, china clay, bentonite, bleaching earth, common clay, ball clay, fire clay, and refractory clay. The different aspects of the definition are explained below. 

Py-GC-MS. The technique of pyrolysis-gas chromatography-mass spectrometry was used to definitively assign the weight loss peaks in TGA by identifying the decomposition products under an inert atmosphere. At least two different pyrolysis temperatures were used for each material in Table II (except for bentonite and TAP-bentonite). In this fashion, isolation and identification of the products evolved during at least two major TGA transitions was possible. Thus, TMPyPCl was pyrolyzed at 420 C and 600 C to determine transitions B and C (by subtraction), respectively transition A is known to be due to water. The temperatures of pyrolysis for all samples are summarized in Table III, along with product assignments. The terms "pyridines" and "anilines" in... 

Definition One of the montmorillonite minerals that are the principal constituent of bentonite clay... 

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