Showing papers on "Vermiculite published in 1970"

Experimental conversion of biotite to hydrobiotite.

Abstract: THE weathering of biotite in the soil frequently leads to replacement of interlayer K+ by hydrated Mg2+, with accompanying structural expansion along the c crystallographic axis from 10 to 14 A (ref. 1). Usually, the 14 A vermiculite phase becomes established without the development of well-defined intermediate spacings on the X-ray diffraction pattern. Biotite, however, sometimes weathers to hydrobiotite2 in which there is a regular alternation of 10 A biotite and 14 A vermiculite units yielding distinct X-ray reflexions at 12 and 24 A. Hydrobiotite may also originate, perhaps more frequently3, through hydrothermal alteration. The vermiculitization of biotite in the laboratory has been extensively studied without observation of an intermediate regularly layered phase4–6, although in one study7 hydrobiotite was detected as a minor component. Complete regular interstratification has only been achieved by reversing the reaction so that vermiculite is converted to a mica-like phase by controlled sorption of K+ and other ions8–10. We have now accomplished the transformation of biotite to hydrobiotite in conditions which throw some light on the mechanism involved.

I.R. Study of Alkyl-Ammonium Vermiculite Complexes

Abstract: Two octyl-ammonium vermiculite complexes with different 001 periodicities have been studied by i.r. spectroscopy. In each case i.r. spectroscopy affords information on the orientation of the-NH3 + groups and the strength of the hydrogen bond between these groups and the silicate oxygen surfaces. Also a perturbation of the vibration of the OH groups of the silicate has been observed that seems to be related to the distance from the center of the layer at which the-NH3 + groups are situated. The i.r. results are discussed in relation to the structural models deduced from X-ray analysis.

Factors affecting potassium fixation and cation exchange capacities of soil vermiculite clays

Abstract: Soil vermiculite clays of varying tetrahedral and octahedral composition and cation exchange capacity (CEC) were examined for their ability to fix K § in both the wet and dry states. Fixation capacity, expressed as per cent of the CEC, in the wet state was fairly high for most samples but it was enhanced greatly upon drying the K saturated samples. This enhancement indicated that each sample contained a number of vermiculite species with different CECs. The vermiculite clays, as a group, exhibited a much higher fixation capacity at a much lower CEC than those of the coarse grained vermiculites. This enhanced fixation is believed due to the diocta- hedral nature of the coarse grained vermiculites. In samples of nearly equal CECs only those con- taining AP § in tetrahedral positions exhibited an enhanced fixation capacity in the dry state but not in the wet state. In was remarkable to find that the state of oxidation of crystal structure iron strongly affected the fixation and the CEC. Reduction of Fe z+ to Fe z+ caused a decrease infixation even though the CEC increased as a result of this change. Conversely these reactions and their effects were found to be reversible. The variation in the orientation of the dipole of the hydroxyl ion in the octahedral layer with respect to the cleavage plane of the crystal is believed to be responsible for some of the noted differences.

Mineralogical Analysis of Clays in Soils Developed from Basalts in Australia

Abstract: Clay mineralogical analyses were made of red soils and black soils developed from southern Victoria, Australia. The clays of the black soils are dominantly montmorillonite (39%) and vermiculite (16%) but have an average siliceous allophane content of 17%. The clays of the red soils are dominantly kaolinite and halloysite (26%) and chlorite (30%) but have an average halloysitic allophane content of 21%. Two to eight per cent of mica and quartz occur in both. A longer period of eolian dust accumulation and concurrent weathering and soil development have occurred in the red soils than in the black soils since the last cycle of geological erosion. A simple chemical method was used for the estimation of allophane (amorphous alumina, silica, and iron oxide with water) and kaolinite plus halloysite. After selective dissolution of allophane, free Al(OH)3, and amorphous SiO2 during 2.5 min of boiling in 0.5N KOH solution, the residue is subjected to heat treatment at 550°C to dehydroxylate the kaolinite and halloysite. This is followed by another 2.5 min dissolution treatment in 0.5N KOH and a further deferration with dithionite. Some iron-rich montmorillonitesaponite (smectite) and vermiculite are also dehydroxylated on heating and subsequently are partially dissolved in the KOH. The kaolinite and halloysite constituents were then calculated.

Fixed ammonium in soils developed on some Queensland phyllites and its relation to weathering.

Abstract: Analyses for native fixed ammonium and for other constituents are reported for four soil profiles developed on Permian phyllite. While total nitrogen contents decreased with depth, fixed ammonium nitrogen increased and reached very high values in each subsoil (one contained 7.7 m-equiv. fixed ammonium nitrogen per 100 g dry soil, or 0.108 % N). Nitrogen-15 enrichments of the fixed ammonium nitrogen were not significantly different from those of N2, in the atmosphere. Fixed ammonium nitrogen in one surface soil was unavailable as a source of nitrogen for Setaria sphacelata. Total potassium also increased with depth and was highly correlated with fixed ammonium nitrogen. On the basis of these results and from clay mineral analyses presented it is suggested that the fixed ammonium nitrogen is present in interlayer sites in illite formed front mica in the parent material. The ammonium/potassium molecular ratio differs for each profile but does not change during the weathering sequence mica -> illite -> vermiculite in any one profile.

Interlayer water in vermiculite: thermodynamic properties, packing density, nuclear pulse resonance, and infra-red absorption

Abstract: Water vapour sorption isotherms on sodium and magnesium vermiculite of high charge density were measured at 25 and 50°C. Heats of immersion at various stages of hydration were measured at 25°C. According to X-ray observations during the sorption process, two discrete interlayer hydrates are obtained with one and two monolayers of water between the unit layers of the crystallites. The derived integral entropy of adsorption indicates a reduced freedom of motion of the interlayer water molecules compared with that for water molecules in the liquid state. Comparison of the apparent density of the hydrated clay with the calculated crystallographic density indicates that interlayer water is slightly more densily packed than liquid water. However, the bulk density of water in a sodium vermiculite suspension is normal for the water in excess of the two hydration layers.Nuclear pulse resonance results obtained on sodium vermiculite shows that water in the one-layer hydrate is organized and some hypotheses are presented regarding this organization. Water molecules in the two-layer complex show the same degree of orientation only below –65°C. Infra-red absorption spectra for hydrated flakes of sodium vermiculite were obtained as a function of angle between the (001) plane of the crystallites and the i.-r. beam. The results indicate orientation of water molecules in the one-layer hydrate at room temperature.

Estimation of surface charge density of mica and vermiculite by competitive adsorption of diquat2+ vs. paraquat2+.

Abstract: Competitive adsorption of diquat²⁺ (1,1′-ethylene-2,2′-dipyridinium ion) vs. paraquat²⁺ (1,1′-dimethyl-4,4′-dipyridinium ion) by external surfaces of vermiculite and mica appeared to be linearly related to the surface charge densities of the adsorbents. This suggested a means for estimating surface charge of soil layer silicates. Soil clays, treated for removal of free iron and kaolin, exhibited surface charge densities in the range 7.3–8.7 × 10⁴ esu/cm².

Method of making glazed ceramic bonded expanded vermiculite articles

Abstract: A method for producing strong low density articles suitable for use as disposable containers by mixing expanded vermiculite and a ceramic material in about equal proportions by weight with water, pressing to the desired shape, drying, coating with an engobe and a glaze and firing to mature the galze and ceramically bond the matrix material with the vermiculite. Suitable matrix materials are clays, talc, fledspar, flint and wollastonite. Optionally pressing lubricants can be used.

Formation and Stability of Hydroxy-Mg Interlayers in Phyllosilicates

Abstract: A study was conducted to (1) determine the conditions of hydroxy-Mg interlayer formation with respect to type of clay mineral, acidity, and time; (2) evaluate the stability of this interlayer to dissolution treatments; and (3) ascertain the effects of such treatments upon the determination of clay minerals in soils and sediments. Hydroxy-Mg interlayers were formed in montmorillonite and vermicu- lite by adding MgCI~ and NaOH in amounts to give a wide range of pH. The resulting chloritic intergrades were examined after 10 days, 6 months, and 1 yr. Alkaline conditions favored the formation of hydroxy magnesium interlayers in phyllosilicates. Hydroxy-Mg interlayered montmoriUonite which resulted from 10 days equilibration at pH 10.4 did not expand upon solvation with ethylene glycol and exhibited practically no collapse after K-saturation and heating at 550~ A small amount of interlayer was formed between pH 6.8 and 9.8 (10 days). In contrast, vermiculite exhibited no evidence of interlayer formation at pH values up to 9-7 (10 days). Chloritic intergrades formed at pH 10-7 did not collapse after K-saturation and heating at 300~ but did so at 550~ Hydroxy-Mg interlayers were not formed in either mineral by using a drying method. This method apparently failed to provide the required alkaline conditions for interlayer formation. The amount of magnesium interlayers present in the phyllosilicate systems decreased with time. The interlayers formed in vermiculite decreased more sharply than those in montmorillonite. Sequential dissolution treatments included boiling 2 per cent Na~CO3, buffered sodium citrate- dithionite, a second citrate-dithionite treatment, and boiling NaOH. Hydroxy-Mg interlayers in montmorillonite exhibited a higher stability to sequential treatments than the interlayers formed in vermiculite. A stable 14 ,~ line was observed in interlayered montmorillonite after the dithionite- citrate and NaOH treatments. The interlayers in montmorillonite showed a relatively high stability to HCI dissolution treatments. In contrast, most of the magnesium interlayer in vermiculite was removed by two HC1 washings. The reagents used in this study are sometimes used to remove coatings and cementing agents from soil surfaces prior to particle size and clay analysis. The present data show that these treatments also remove some hydroxy-Mg interlayers and produce changes in properties of clays, A proper interpre- tation of data for clay mineral identification and characterization must recognize these changes due to treatment. HYDROXY-Mg interlayers in phyllosilicates would be expected to occur in soils (Brydon, et al., 1961) and marine sediments (Rich, 1968), but they have received little attention compared to aluminum interlayers. Singleton (1965) reported the presence of hydroxy-Mg in addition to hydroxy-Al and -Fe in the interlayer space of clays from the Lookout series in Oregon. The formation of secondary chlorite in the dark magnesium clay soils of Hawaii and in Grumusols (Ladybrook Series) of Queens- land, Australia, was related to the hydroxy-Mg interlayering in montmorillonite (Jackson, 1959).

Chemical, physical and mineralogical properties of a podzol soil with fragipan derived from glacial till in the province of quebec

Abstract: From chemical analyses performed on an Arago profile, it met the requirements of the Podzol order, except for exchange properties. The cation exchange capacity was low and the ΔCEC never reached the limit of 8 meq/100 g. Qualitative and quantitative mineralogical analyses showed that illite was the predominant component of the fine fraction throughout the profile. Weathering from non-expanding 2:1 minerals to expanding ones occurred in the upper horizons. Two types of clay mineral interstratification were observed. The first type, present in the whole profile, was a randomly interstratified illite-montmorillonite complex. The second was a mixed-layer mineral formed by chlorite and vermiculite. It was found mainly in the fragipan and, to a lesser extent, in the parent material. From the mineral distribution, the pan firmness was not necessarily related to the presence of illite.

Cation exchange properties of micas. III. Release of potassium sorbed by potassium-depleted micas.

Abstract: Two phlogopites depleted of potassium by extraction with sodium tetraphenyl boron released resorbed potassium more readily than the original micas, but the large difference in the exchange parameters of the two micas were paralleled by those of their potassium-saturated alteration products. The apparent basal spacings of the potassium-saturated alteration products were about 0"03A larger than those of the corresponding untreated micas; their broader lines indicate structural irregularities. There are conflicting views about the release of added K from vermiculites and from K-depleted micas. Barshad (1948) suggested that biotite and vermiculite could be int~rconverted, and this suggestion has been repeated from time to time (e.g. Rhoades & Coleman, 1967), but Ellis & Mortland (1959) found that 'fixed', i.e. added I(, exchanged more readily than 'native', i.e. mica K. The previous paper (Part II) in this series (Newman, 1970) showed that the exchange of mica-K is not reversible, and this seemed to be partly because of irreversible alteration in the mica. We present here further evidence of irreversible alteration, obtained by comparing the exchange parameters and structural properties of unaltered micas and their K-saturated alteration products.

Syntheses of montmorillonites and vermiculite-like minerals from sericite and pyrophyllite

Abstract: Montmorillonite minerals and vermiculite-like minerals were synthesized from sericite and pyrophyllite under hydrothermal condition at 290°C and 110kg/cm2 for periods of three hours. Formation of these minerals is favoured by alkaline conditions and the presence of proper amount of magnesium ion.

Process for the use of vermiculite in waste water renovation

Abstract: VERMICULITE, AFTER HAVING BEEN CHEMICALLY TREATED, HAS ENHANCED ABSORPTIVE AND COAGULATIVE PROPERTIES, AND CAN BE USED TO REMOVE CONTAMINATES OCCURING IN WASTE WATERS BY REMOVING PHOSPHATES FROM THE WASTE WATER. THE TREATMENT CONSISTS OF (1) EXPANDING THE VERMICULITE AND (2) TREATING THE EXPANDED VERMICULITE WITH AN AQUEOUS SOLUTION OF AN INORGANIC SALT, THE CATION OF WHICH IS IN A +2 OR HIGHER VALENCE STATE.

Formation of vermiculite and kaolin mineral from hornblende

Abstract: Vermiculite and kaolin mineral showing a single crystal pseudomorph of hornblende are found in the hornblende andesite distributed in Iriki-cho, northern part of Kagoshima Prefecture. The vermiculite was formed from hornblende and then the kaolin mineral was formed from the vermiculite by weathering. Zoning due to successive argillization is observed in the crystal.

Plaster containing perlite on vermiculite - sand water and cellulose derivatives

Abstract: Building plaster with low specific wt (075-135), increased fireproofness, heat- and sound-insulating properties, contains fine-grained porous mineral (I) (such as perlite, vermiculite or heat-treated expanded material and/or powdered light concrete) in addn to sand, water and a water-soluble deriv Pref (I) content is >3wt%/wt total composn Pref composn contains 15-30 (more pref 10-30)% water, 20-50 (20-45)% sand, 2-25% pptd chalk or esp CaSO41/2H2O, 5-45% (I) and 03-2 (05-2)% cellulose deriv and esp also a water-insoluble binder such as polyacrylic acid (increases adhesion) and is pref packed and sealed in water-, steam- and air-impermeable material

An aspect on interlayer potassium of mica minerals in soils

Abstract: Cosiderable amount of mica minerals holding potassium in interlayer region occurs in clay fraction of various soils. In general, mica-type lattice structure of minerals has remained in certain case as forming interstratified mineral With 14A-spacing minerals such as vermiculite, montmorillonite and chlorite, and in other case they are existing as such. It is interesting and important to discuss the property of interlayer Potassium of mica minerals in soils comparing With that of minerals, geological origin, from a view point of potassium availability of soil. pedogenesis and weathering.

Texture coating composition of polyvinyl acetate emulsion,asbestos and portland cement

Abstract: A NEW TEXTURED COATING HAVING A RANDOM STUCCO-LIKE APPEARANCE FORMED FROM ASBESTOS AND PORTLAND CEMENT DISPERSED IN A POLYVINYL ACETATE OR ETHYLENE MODIFIED POLYVINYL ACETATE EMULSION. THE ABOVE COATING COMPOSITION CAN ALSO CONTAIN OTHER MINERAL FILLERS, SUCH AS PERLITE, SAND AND VERMICULITE.