Dry Clay Research Articles

Kaolin refractories with a minimum amount of clay bond

When dry bond clay and some of the normal fine-ground chamotte are replaced by chamotte which has been finely ground with the addition of 0.1% C7-C9 acid for the same amount of grinding time, and when clay is added solely in the form of dross, it is possible to obtain dry specimens with a porosity of only 2% more and fired specimens in no way inferior in density to the control specimens, but even with less porosity after firing, though the shrink-age is slightly increased. Hydrophobization of the chamotte fractions 2–0.5 mm without the addition of dried clay makes it possible to obtain fired specimens showing the same properties as the control ones, and less porous ones, though there is slightly increased shrinkage. The replacement of the clay bond added to the mixture in dry form by fine-ground hydrophobized chamotte sharply reduces the after-effect in these mixtures during pressing. The possibility has been established, in principle, of obtaining multichamotte parts from kaolinite raw materials by the addition of bond clay to the mixtures in the proportion of 2–4% in the form of dross alone. The industrial production of these parts should be of practical interest since an increase in the alumina content and a reduction in the flux content in parts is thereby achieved; an increase in the efficiency of tube mills and the degree of dispersion of the fine-ground chamotte on account of being ground without clay and the addition of a dehardener, and a simplification of the production process by eliminating the preparation of the clay for the bond are also made possible. The results and the behavior of parts during service should be tested under semi-plant and plant conditions. Here tests should be made on replacing all the ordinary fine-ground chamotte by chamotte ground with a hydro-phobizer, since this will simplify the production process still more. The manufacture and testing of experimental-industrial batches of parts by the proposed method should be organized together with the UNIIO.

SORPTION BY THE EARTH SURFACE AND A NEW CLASSIFICATION OF KATA-HYDROMETEORIC PROCESSES

It is proposed to call all processes bringing water of any phase to the surface kata-hydrometeoric processes.Their classification includes, e.g., intercepted precipitation, dew and at least five forms of sorption. Specialemphasis is then given to some generally neglected sorptive processes. Sorptive water intake can be calculatedby using Hofmann's dew formulae if the relative humidity of the surface is supposed to be less than 100per cent. Soil, plants and water solutions have known sorptive qualities; the most important process inpractice is adsorption by dry clay. Field tests in India, Ohio, Nebraska and Texas show strong soil sorptionespecially on the late afternoons of sunny days. This sorption seems also responsible for fog prevention alongthe Gulf Coast on summer nights.

Plastic deformation of nearly dry clay, and relations between water content and modules of rupture and relations between water content and modules of rupture and modules of elasticity

A method for determing the strength and elasticity of clay bar is given, and determined the moisture content at which a plastic body becomes elastic. Not only strength but also elasticy of nearly dry clay are important for handling the clay body under working conditions. The theoretical consideration is also discussed for the flow property of a nearly dry clay body.

Lattice Expansion and Rheological Behavior Relationships in Water-Montmorillonite Systems

AbstractSome divergent experimental data have been reported on the swelling behavior of sodium montmorillonite. At water contents above 50 percent (based on the weight of dry clay) the basal reflection of sodium montmorillonite at 19.2 Å becomes weak and very diffuse; some workers have stated that it disappears altogether while others report a persistent weak line even at very high water content. The pronounced differences in physical properties of sodium and calcium montmorillonite suggest that their lattice expansions should also be dissimilar. This paper describes some X-ray diffraction experiments using purified lithium, sodium, and potassium montmorillonites dispersed in water and in salt solutions which were conducted for the purpose of resolving some of these disputed points. The X-ray diffraction instrument employed was a General Electric geiger counter spectrometer unit with a copper tube and nickel filters. The knowledge thus gained has provided some insight into other properties of these clays, such as their rheological behavior.A recording Couette-type viscometer designed to provide a wide spectrum of shear rates and shearing stresses has been used to examine the rheological transformations which occur in passing from states of maximum dispersion to states of varying degrees of agglomeration as a result of interactions between LiCl, NaCl, KCl, and CaCl2, and the Li, Na, K, and Ca salts of montmorillonite in terms of certain ideal rheological models. Filtration characteristics of these systems have also been explored using a standard technique.

Measurement of Dry Strength of Clay Bodies

Factors affecting the measured modulus of rupture of unfired clay bars were studied. These included the following variables: mixing time and aging of plastic clay; minor modifications in extrusion‐machine design; and span width, rate of load application, and diameter of test bar used in cross‐breaking machine. It was also found that exposure of dry clay bars to atmospheres of increasing per cent relative humidity decreased their strength values significantly.

On the Dielectric Constant of the Water in Wet Clay

Some recent experimental values of the variation of the dielectric constant of wet clay with moisture content cannot be explained on the assumption that the clay particles and water molecules form a simple mixture. The results can, however, be theoretically deduced by considering relatively dry clay to consist of closely packed water-coated clay particles in an air matrix and relatively wet clay to consist of clay particles uniformly distributed in a water matrix, the water associated with the clay having an effective dielectric constant which varies exponentially from that of `bound' water (about 3) to that of `free' water (about 80) as the percentage of water is gradually increased The conclusion follows that water films have a very low dielectric constant compared with that of water in bulk.

COMPACTION OF SOILS.

Synopsis. Soil compaction is the process whereby soil is mechanically compressed through a reduction in the air voids. It is measured in terms of the dry density or amount of solid matter in unit volume. Soils range in dry density from about 140 lb. per cubic foot for coarse-grained gravels and sands to about 90 lb. per cubic foot for heavy clays. For a constant amount of compaction, all soils have an optimum moisture content at which a maximum dry density is obtained. The leboratory tests used to determine the compaction characteristics are described in this Paper and factors affecting their results are discussed. In the field, compaction is effected by different types of roller, rammer, or vibrator. The results of full-scale investigations which have been made at the Road Research and sheepfoot rollers, a frog rammer, and vibrating plant, are discussed. The main Laboratory of the compaction of five British soils by smooth-wheel, pneumatic-tired, conclusions are that:— (l) There is an optimum moisture content for each type of plant which may differ hm that indicated by laboratory tests. (2) Granular soils are best compacted by smooth-wheel rollers, wet clay soils by pneumatic-tired rollers, and dry clay soils by sheepsfoot rollers. (3) Provided that the thickness of loose layer does not exceed 9 inches, the decrease of dry density with depth below the surface was about the same for all the rollers tested. A suggested procedure is outlined for carrying out full-scale compaction trials on a job, and an example of its use is given.

NOTE ON AN ERRATIC BLOCK AT RANDY MERE, NEAR GOATHLAND, YORKSHIRE

The erratic block described in this note was encountered in a tunnel driven to accommodate a water main from Randy Mere Reservoir, Whitby Waterworks (one-inch sheet 43, six-inch sheet Yorks. 45 SE). Specimens for identification were sent to the Geological Museum by Mr. Hallimond who furnished certain details of its position; Mr. Taylor, secretary of the Whitby Water Company, also supplied information and specimens. The rock proved to be a porphyritic andesite of the Borrowdale Volcanic Series. The tunnel, 3ft. 6in. square, met the erratic, which was embedded in a dry grey clay, at 23ft. 9in. from the surface just north of the north boundary of the reservoir property. Up to this point the tunnel was cut mainly through running sand, the only foreign material met being sandstone. At first an attempt was made to cut through the obstacle but this was found too difficult and the heading was diverted to the east. When clear of the rock the heading was brought back to its original line. In this way a minimum length of fourteen feet of rock was ascertained, while the minimum thickness was that of the tunnel, namely three feet six inches. The actual dimensions of this large erratic are not known. In hand specimen the erratic is a greyish-green rock speckled with abundant whitish feldspars up to 3 mm. in length and with less numerous black prisms about 1 mm. long. In another sample the distinction between the larger components and the matrix is not so clear; ...

A Soil Borer that Penetrates Dry and Hard Clay Soil

Agronomy JournalVolume 33, Issue 5 p. 476-476 Note A Soil Borer that Penetrates Dry and Hard Clay Soil Antti Saliminen, Antti Saliminen Soil Division, Central Agricultural Experiment Station, Helsinki, FinlandSearch for more papers by this author Antti Saliminen, Antti Saliminen Soil Division, Central Agricultural Experiment Station, Helsinki, FinlandSearch for more papers by this author First published: 01 May 1941 https://doi.org/10.2134/agronj1941.00021962003300050013xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume33, Issue5May 1941Pages 476-476 RelatedInformation

ROOT SYSTEMS OF BRIGHT BELT TOBACCO

ROOT SYSTEMS OF BRIGHT BELT TOBACCO

NATURE AND PROPERTIES OF YAMAGATA BENTONITE

The following are the results of my study on a certain yellow species of the Yamagata bentonite.(1). A water imbibing mass at the swelling equilibrium (25.0°C) contains 0.359g of dry clay per 100g of the mass, and its calculated values of sp. volume and swelling ratio are 0.980cc and 1:73.0 respectively.(2). On adding ample water an abnormally rapid swelling is observed on the surface of a dry or partially imbibing clay mass. Let us call the swelling “surface swelling”. The surface swelling, with some quickness, takes an equilibrium which correspond to a terrace, nearer to the origin, on the time-swelling curve, and leaves a gelatineous thin film on the surface, a film completely covering the surface, insists against further penetration of water. A time interval to reach the equilibrium of the surface swelling becomes shorter both with the increase of initial distribution density of surface particle and with dryness or concentration of the mass of clay, and yet the gel film thickens with the shortened time interval just mentioned.(3). A film of bentonite, 0.1-0.05mm thick, does a directional swelling, viz., at the swelling equilibrium the ratio of swelling is 1:39.0 in the direction of thickness and 1:1.37 in that of spreading.(4). The swelling velocity of film, in both directions, may well be denoted by the following equation:di/dtk(i∞-it)Here, it is a ratio of swelling at any time interval t, and i∞ another at infinite time, k being a constant of proportionality. This equation is quite the same as that of simple chemical reaction velocity.(5). On considering a mechanism of film formation we can infer a type of bentonite micelle model. The model has a layer structure which can be exemplified by a alternative film layer of Al-hexite an Si-hexite, and it has almost the same structure as the crystal structure of kaolinite or some base-exchange type clay.

A SIMPLE DISPERSION TEST FOR CLAYS*

A test method was devised to indicate the comparative degree of dispersion of dry clay by simple blunging and removal of particles finer than 325-mesh. Tests of seven kaolins and one ball clay are given.

A QUICK METHOD OF DETERMINING THE WATER CONTENT OF CLAYS1

The water content of clay is determined by taking a representative sample of the material, weighing out 2 kg. of it and adding 4 kg. of water. The sample is blunged quickly. A 250-cc. flask is filled with the resulting slip and weighed. The amount of dry clay is determined from the relation: D= (P−250)(G/G−1) where D= weight of dry clay P= weight of slip G= specific gravity of dry clay. From this the per cent water in the moist clay is readily computed.

Apparatus for determining the specific heat of a material in powder form

A calorimeter suitable for heavy powdered materials, such as dry clay, is described. It utilises the electrical method, and embodies a special form of stirrer suitable for these materials.

SOME OBSERVATIONS ON THE DRYING PROPERTIES OF CLAYS1

This is a preliminary report. After calling attention to some phenomena brought out, the authors discuss the effects of shape, temperature, vapor pressure, humidity and the velocity of air currents as affecting the rate of drying. It is shown that evaporation from the clay sample is directly proportional to surface area exposed per unit weight of the dry clay body and that successful drying is a function of the rate of drying, but a different function for each different type of clay. Data are presented on the relation of transverse breaking strength to residual moisture content for each of several typical clays. The causes of the varying types of drying injuries are pointed out, sample drying schedules are given and a method is suggested whereby the clayworker may without great expense quickly work out for himself in the laboratory the most rapid and safe drying schedules possible for his particular type of material regardless of its character or its source, and to alter his drying practice so as to overcome present difficulties. Brief descriptions are given of the drying cabinet used and of a simple weighing device for automatically indicating, through loss of weight, the amount of moisture already evaporated and the amount of shrinkage the clay has undergone at any moment of observation during the drying process. The information supplied should operate to bring about a reduction in production costs of clay products, and hence of selling prices, to the ultimate consumer. A brief outline of the proposed extension of the investigation is given in the conclusion.

On some sections of boulder clay, peat, and stratified beds recently exposed at Redhal, Slateford, near Edinburgh

The new quarry in which these sections are exposed lies to the north of the quarry, hitherto called Redhall Quarry, and is separated from it by the canal and the Caledonian Railway. Both quarries are in the same line of strike in the carboniferous rocks, which dip to the west along this line. Unfortunately, a large portion of the beds overlying the sandstone had been removed before I saw the sections, and the process of sloping the banks had been going on for some time—a very unlucky proceeding for the geologist. Still, there was enough left to show the very interesting and instructive sections we have in this locality. At the south end of the quarry, where the process of tirring was going on when I first observed it, the sandstone beds, as I have remarked, dip to the west. At the east side of the section the beds are sharp, unweathered, and truncated, the spaces between the ends of the beds being firmly packed with hard, dry boulder clay, full of both angular and rubbed stones. The two lowest beds of sandstone exposed are each four or five feet thick. The ends of these beds are also truncated, showing as it were a cliff from eight to ten feet deep, facing the east. This is also filled up with boulder clay, enclosing large angular blocks of sandstone, evidently derived from the end of the beds, and also a large number of smaller stones, scarcely any of them rubbed or

On the American Dry Clay Brick-Making Machine

On the American Dry Clay Brick-Making Machine