Bulletin - Division of Mineral Resources, Ausgabe 13North Carolina. Division of Mineral Resources, North Carolina. Department of Conservation and Development North Carolina, Department of Conservation and Development, Division of Mineral Resources, 1897 |
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air-dried briquettes Alkalies Alumina Alumina Ferric oxide amount average tensile strength Brick-clay calcium carbonate cent chemical Clay substance coarse color composition COUNTY cubic centimetres dense drying feet feldspar Ferric oxide ferrous fine-grained fire-clay fluxes Specific gravity Free sand fusible give a workable giving a total grains Grover GUILFORD COUNTY heat Incipient fusion occurs iron K₂O kaolinite kiln lean Lincolnton loss on ignition Magnesia manufacture maximum mica miles mineral mixture Moisture Silica total molded North Carolina North Carolina clays occurs at 1900 organic matter paste shrunk paving brick percentage Pomona Terracotta Pottery Clay Prospect Hall pugmill quartz quartz and feldspar residual clays river sample sandy clay sedimentary clays sewer-pipe SiO2 slakes slowly Specific gravity Spout Springs square inch stiff-mud stoneware sulphate sulphuric acid temperature total shrinkage trough vein viscosity viscosity at 2300 vitrification vitrification at 2100 ware washed kaolin Water loss Webster workable paste
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Seite 28 - The filtrate from the silica is divided into equal portions. To one portion in a reducing flask is added metallic zinc and sulphuric acid. After reduction and filtration to free the liquid from undissolved zinc -and carbon, the iron is determined by titration with a standard solution of potassium permanganate. Aluminium...
Seite 55 - ... break up the clay, which is charged through a hopper at the top. A current of water passes through the cylinder and carries the fine clay particles with it, while the coarse ones are left behind in the machine. The speed of the current has to be regulated by experiment, for if too much water is used coarse material will be washed out of the cylinder, and conversely if the current is too slow the clay will not yield a sufficient percentage of washed product. One objection to this apparatus is...
Seite 38 - As at present put on the market, the thermoelectric pyrometer costs about $180, and the price, together with the delicacy of the galvanometer, has tended to restrict its use. There is no reason however why one should not be made and put on the market for a much lower price. It is not necessary that the recording...
Seite 18 - Carolina clays the combined alkalies (potash and soda) vary from .29$ in clay from Spout Springs to 4.62$ in brick clay from Wilkesboro. The average is 1.50 to 2.5$. The washed kaolins usually contain under one per cent. The pottery clays of North Carolina have from 0.68 to 2.82$. COMPOUNDS OF IRON IN CLAY. Aside from being a flux, iron oxide is also the great natural coloring agent of clays in both their raw and burned state. The mineral compounds which may serve as the sources of iron oxides in...
Seite 77 - Ibs. per square inch. Incipient fusion occurs at 1900° F., vitrification at 2100° F., and viscosity at 2300° F. The clay burns to...
Seite 56 - These sand-wheels are a help, but it is often necessary in addition to keep a man shoveling the sand from the trough. If the sand is finer it is not dropped so quickly and, distributed more evenly along the trough, does not clog it up so fast. The zigzag arrangement of the troughing has been objected to by some as it produces irregularities in the current, causing the sand to bank up in the corners, at the bends and at certain points along the sides of the troughing.
Seite 56 - ... times the width, and divided by several longitudinal partitions. The water and the clay then pass into a third section, twice as wide as the second, and divided by twice the number of longitudinal divisions. By this means the water moves only in a straight course, but as it is being continually spread out over a wider space, it flows with an ever-decreasing velocity.
Seite 34 - Olchewsky 5 was probably the first to suggest that the plasticity and cohesion of a clay were dependent on the interlocking of the clay particles and kaolinite plates, and in this connection used the briquette method of testing the plasticity, or rather obtaining a numerical expression for it, by determining the tensile strength of the air-dried clay.
Seite 22 - In general, it may be said that a good brick can be made from a clay containing 20 to 25$ of calcium carbonate, provided it is evenly distributed through the clay and in as finely a divided state as possible.
Seite 27 - ... added, and filtered through a Gooch crucible or upon a tared filter paper. The precipitate is thoroughly washed with eighty per cent, alcohol, dried at 100° C. and weighed ; the potassium oxide is calculated from the double chloride of potassium and platinum. When magnesium was present to as much as onehalf of one per cent., the magnesium hydroxide was precipitated with barium hydroxide solution and the barium in turn removed by ammonium carbonate. When the amount of magnesium was less than...