著者
岡田 清
出版者
日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.50, no.3, 2012-03-30
著者
田崎 和江
出版者
日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.35, no.3, 1995-12-28
被引用文献数
1
著者
北川 隆司
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.39, no.1, pp.37-44, 1999-06-30 (Released:2011-09-20)
参考文献数
56
被引用文献数
3
著者
佐伯 和利
出版者
日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.45, no.2, pp.90-94, 2006-03-06
被引用文献数
5

In order to understand the adsorptive selectivities of heavy metal species on constituents of soil, adsorptions of heavy metal ions (Cd^<2+>, Co^<2+>, Cu^<2+>, Ni^<2+>, Pb^<2+> and Zn^<2+>) on a variable charge material, silica which have a surface functional group, Si-OH, were investigated as a function of the solution pH,. The comparative sorption study with Ca^<2+> were also carried out in the similar manners. The adsorptive affinities of the divalent metal ions on silica were numbered with intrinsic surface complexation constants (K_m^1 (int)) calculated approximately from the adsorptive data using a constant capacitance model. Experiments of Cd and Pb adsorptions were carried out in a 0.1 mol L^<-1> (M) NaNO_3 background solution because a chemical speciation model, SOILCHEM estimated that each proportion of free ions of the metals would be low in a 0.1 M NaCl background solution. The other metal's adsorption experiments used a 0.1 M NaCl background solution. The higher pH the suspension raised, the more heavy metal ions were adsorbed. The adsorptions of the heavy metals increased rapidly from 0 to 100% in narrow pH range (about 2 pH units). The heavy metal ions differed from Ca^<2+> in their great adsorptions at higher pH. Judging from the K_m^1 (int) of each divalent metal ion, the selective order for the metal adsorption by silica was Pb > Cu > Zn > Ni > Cd > Co >> Ca. In addition of the data for Fe^<2+> and Mn^<2+> in my previous study (Saeki, 2004), the order of the nine metals was Pb > Cu > Fe > Zn > Ni > Cd > Mn > Co >> Ca.
著者
大森 啓一 岡田 広吉
出版者
一般社団法人 日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.18, no.2, pp.40-50, 1978-06-25 (Released:2011-09-20)
参考文献数
9

An old castle named Tagajo was founded between the 8th and 11th Centuries in Miyage Prefecture, Japan. Roofing tiles were unearthed from the ruins of castle and old oven, which were studied by mineralogical methods.Roofing tiles used in the study were classified from archaeology into two groups, one of which was the I era tiles and the other the II, III and IV era tiles. Every tiles were 12 to 34mm in thickness. The I tiles were homogeneous with light dark color and the others inhomogeneous roughly with ashy color. In every tiles many porphyritic quartz crystals were found in association with plagioclase, hornblende, augite and magnetite under a microscope. Their groundmasses consisted of quartz and glassy materials.Textures were found to be fluidal, banded and microfolded in the I tiles, and were more notable than those of the II to IV tiles. From X-ray diffraction patterns the presence of quartz, plagioclase, cristobalite and mullite was detected. From chemical analyses all compositions concentrated on a small area centered at 70% SiO2, 20% Al203 and 10% the others in the triangle phase diagram. Refractorinesses of every tiles were found to be under SK 26. Water absorptions of these tiles satisfies a requirement of the JIS standard for roofing tiles.From these results it was found that the fired temperatures were between 1, 000° and 1, 200°C and the techniques making roofing tiles progressed from the I era to the II to IV eras.

1 0 0 0 OA 粘土と耐火物

著者
林 武志
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.18, no.3, pp.105-115, 1978-09-25 (Released:2011-09-20)

Clay has played an important role in the refractories industry because of its special properties such as favorable plasticity, good sinterability and low cost. An outline of fire clay refractories and the features of clays are mentioned in this paper.The principal chemical composition of clays is silica, alumina and water, and these consist mineralogically of kaoline mineral and quartz. Clays also contain impurities, for example iron oxide, potassium oxide, and sodium oxide, and therefore also contain feldspar, sericite and pyrophyllite.In industrial ceramics, clays are used two ways. One way is the dead burning of clays which is used for large grog or refractory grain particles in fire clay refractories. The process requires special properties such as high density and high temperature stability. In the second way, clays are used for binder for which it is necessary to have favorable plasticity.Fire clay refractories are composed of refractory grain particles of burned clay and binder clay, their properties are decided by the raw materials and heat treatment used.The chemical composition of fire clay refractories are silica, alumina and accessary components which are the same as clays, and these mineralogically consist of mullite, cristobalite and a glass phase.This fact suggests that the kinds and quantity of impurity contained in the formation of cristobalite give a marked effect on the shrinkage, tightening and the spalling of a ceramic body.Damage in fire clay refractories can be observed during service in the following cases; 1) presence of impurities which cause the formation of glass, 2) thermal expansion spalling due to the presence of cristobalite, 3) alkali attack in the blast furnace, 4) bloating phenomena in the ladle.
著者
田崎 和江 国峯 由貴江 森川 俊和
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.41, no.2, pp.64-74, 2001-12-31 (Released:2011-09-20)
参考文献数
29
被引用文献数
1

In 1985, Dashidaira dam with discharge gate had been built for the first time in Japan, at Kurobe River in Toyama Prefecture. Six years later, in 1991, the dam sediments were flushed out for the first time and impacted on the downstream of Kurobe River. The dam sediments and the suspension contained a large amount of organic matter (with high C, N and S contents) with sludge-smell. The annual catch of bentic fishes (exp. flatfish) and the annual haul of wakame seaweed have been decreased year by year since the first discharge of the dam sediments in 1991. Until now, it has been reported that the sludge has deposited in the Toyama Bay which is apprehensive of influence of discharged dam sediments, because suspended particles affect the fish's gill respiration.In this study, suspension of river water were collected at three bridges during discharge from Dashidaira and Unazuki Dam in June 19th-22nd and in June 30th-July 2nd, 2001. River water quality and suspended solid were analyzed chemically, physically and mineralogically. Extremely low DO and Eh values were observed at the periods during first discharge in June 19th-22nd at two bridges. Moreover, during second discharge in June 30th-July 2nd, DO and Eh values were constant. Therefore it was shown that drastic decreased of DO and Eh values were a peculiar phenomenon during first discharge in June 19th-22th, 2001. The results of NCS elemental analyses were suggested that high organic contents were related with drastic decreased of DO and Eh values. Clay mineralogy of both Unazuki Dam sediments and suspended solid on the seabed at the offing of Kurobe River mouth, show abundant semctite with chlorite, mica clay minerals and kaolin minerals, suggesting those are the almost same origin. The dam sediments associated with organic matter impacted on downstream and the seabed, and was the cause of affecting bentic fishes and wakame seaweed.
著者
立山 博
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.34, no.3, pp.157-164, 1994-12-30 (Released:2011-09-20)
参考文献数
13

The morphology of the colloidal particles influences the properties of suspensions, particularly the viscosity and plasticity that seem to increase with the presence of platelike colloidal particles. Shear stress is calculated against shear rate in dilute clay-water suspensions on the basis of Simha's theory, which indicates that the rheological behavior ofplatelike particles is different from that of spherical particles. In the case of condensed suspensions, platelike particles are flocculated into some different associations, then the rheological behaviour of the suspensions becomes very complicated. Normarized orientational function is used to predict the properties of flocculated structure in the present report. Shear stress is simulated using the equation of total energy dissipation rate based on the Michael's theory.
著者
下山 晃
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.21, no.3, pp.93-101, 1981-10-20 (Released:2011-09-20)
参考文献数
32
被引用文献数
1

Chemical evolution postulates the prebiotic formation of organic compounds and their accumulation as a necessary preamble to the appearance of life on the earth. Of the surface constituents on the primitive earth, clay minerals may have contributed to the process of chemical evolution because of their wide distribution in geological time and space and their strong affinity for organic compounds.The possible role of clay minerals in the different stages of chemical evolution may include 1) catalysis in the reaction of monomer synthesis from gaseous constituents of the primordal atmosphere, 2) adsorption of the monomers on their surface, providing a highly concentrated system with specific monomers, 3) dehydration-condensation in polymerization of the monomers to biologically important polymers, and 4) formation of organo-clay complexes through which some replicating systems may evolve. Of these roles, the monomer formation, adsorption, and polycondensation processes are discussed in this paper with particular emphasis on amino acids, peptides, and proteins.A simulation experiment of prebiotic amino acid formation produced both protein and non-protein amino acids and their racemic mixtures in the presence of montmorillonite. The role of the clay is to promote the formation of amino acids of greater carbon numbers. Adsorption experiments show that there is no selection of protein amino acids over non-protein ones by the clay. However, α-amino acids are less adsorbed than non-α-amino acids under neutral or acidic soluton pH. Neither of D-or L-enantiomers are adsorbed preferentially by the clay, although some reports claim that clay minerals (kaolinite and montmorillonite) can adsorb L-enantiomers selectively. Under fluctuating wet/dry cycles clay minerals can polymerize amino acids upto oligomers, acting probably as a dehydration-condensation agent. The interlayer surfaces and edges of clay minerals are unique areas for chemical evolution and should be investigated more in the study of prebiotic chemistry.
著者
歌田 実 清水 正明
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.30, no.1, pp.11-18, 1990-04-24 (Released:2011-09-20)
参考文献数
13

In the Izu Peninsula, central Japan, seventeen species of zeolites mainly occur in volcanic rocks and volcaniclastic sediments of Miocece to Pleistocene in age. Pervasive zeolites are wairakite, laumontite, heulandite, stilbite, and chabazite and minor are yugawaralite, scolecite, epistilbite. They occur in veins, fractures and druses and are zonally distributed in hydrothermal alteration zones trending NW-SE and NE-SW.Na-zeolites such as clinoptilolite, mordenite, analcime and ferrierite mainly replace vitric materials in volcaniclastic sediments. They were probably formed by thermal effects of magma which intruded at very shallow places during Pliocene to Pleistocene age.There are few localities of fibrous zeolites such as natrolite, mesolite, and thomsollite.
著者
関根 知子
出版者
一般社団法人 日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.54, no.1, pp.1-8, 2015-08-21 (Released:2017-06-22)

Liquid paraffin was added to 3 kinds of smectite dispersions containing different amount of salt to prepare emulsions. Stable emulsions were obtained when the smectite particles aggregated to make the dispersions turbid or almost were segregated with salt. Smectite and cationic cellulose were mixed and then the mixtures were investigated as salt tolerance thickener and emulsifier. The smectite-cationic polymer complex could act as thickener even if the complex dispersion contained 3 wt% of NaCl. The complex dispersion viscosity increased as the molecular weight of the added cationic polymer increased. Finer droplet emulsion was obtained with smectite-cationic cellulose complex containing 3wt% NaCl compared to the smectite emulsion.
著者
鶴田 康生 大久保 利長 小見山 登 吉田 募 上田 智 小泉 光恵
出版者
The Clay Science Society of Japan
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.21, no.4, pp.153-159, 1981-12-25 (Released:2011-09-20)
参考文献数
5

The softening effect of bentonite to cotton fabric was studied in relation to the cation exchange capacity and other characteristics.It could not decide any appreciable corelations between the softening effect andthe ation exchange capacity, speciific surface area, apparent viscocity and the composition of exchangeable cations. Cristobalite associated montmorillonites were adsorbed on to cotton fabric intensifying the softness to the touch.
著者
金城 和俊 島田 晴加
出版者
一般社団法人 日本粘土学会
雑誌
粘土科学
巻号頁・発行日
vol.56, no.1, pp.1-7, 2017

<p>Minami-daito island, which is situated in a sub-tropical area, contains red-yellow soil. Recently, grayish white-colored soil was discovered around dead roots in the subsoil on the island. In general, grayish white-colored soil is formed via iron dissolution by a low molecular-weight aliphatic carboxylic acid solution (LACA) in a cold setting; however, there were few studies regarding the formation of white-colored soil in sub-tropical areas. The objective of this study is to elucidate the mechanism of grayish white-colored soil formation in the sub-tropical setting of Minami-daito island. Soil samples (horizons Ap<sub>1</sub>, Ap<sub>2</sub>, B<sub>1</sub>, and B<sub>2</sub>) were obtained from a pumpkin field on Minami-daito island. Grayish white-colored soil was discovered around dead roots in the B<sub>2</sub> horizon, which was also collected. From X-ray analysis, the clay minerals were kaolin minerals, mica, vermiculite, vermiculite–chlorite integrate, and goethite in the A and B horizons; however, goethite was not present in the white-colored soil. This result indicates that the grayish white-colored soil was formed by the dissolution of goethite around dead roots. It is likely that LACA is necessary for the dissolution of goethite in soil. To prove this hypothesis, a leaching test was conducted. Oxalic acid, formic acid, and acetic acid in LACA and samples of the B<sub>2</sub> soil horizon were used for the leaching test. Compared with H<sub>2</sub>O treatment, Al and Fe were dissolved using LACA treatment and oxalic acid solution treatment. From X-ray analysis, it was observed that the gibbsite and goethite peaks obtained using LACA treatment were smaller than that using H<sub>2</sub>O treatment. In particular, the goethite peak disappeared after oxalic acid treatment. Previous studies have demonstrated that oxalic acid has a high ability to dissolve goethite. It is concluded that the grayish white-colored soil on Minami-daito island was formed via the dissolution of goethite by oxalic acid from plant dead roots.</p>