Glaze G#44 (A) Blue- Conrad's collection, 8/8/08 (C) Black (B) Felspar, Custer 41 (D) Temperature = C/3-5 Ox or Rd (F) Cornwall stone 25 (E) Surface = High gloss (G) Gerstley borate 25 Transparency = Translucent (H) Edgar Plastic 04 Fluidity = Little flow (I) Kaolin Zinc oxide 03 Colour = Clear (J) Lithium 02 Toxicity = Avoid breathing dust (K) carbonate 100(M) Application techniques = Brush 3 thin coats (L) Glue (CMC) (N) Notes: (O) Unity formula (P) GG#44 [above] 100 (Q) Copper oxide 04 (R) Surface = High gloss (G) Cobalt oxide 02 Transparency = Opaque (H) Granular Fluidity = Little flow (I) magnetite Colour = Blue-black (J) trace Glaze appl.
Formula #1 Potash felspar 48 Spodumene 05 Whiting 14 Kaolin 14 Silica 19 100 Copper carbonate 02 CMC added Formula #2 Custer felspar 177.
Grim (1968) referred to the formation of kaolin as kaolinisation, that is, kaolinite is formed from the decomposition of felspar (potassium felspar), granite and alumina silicate which occurs in three different ways:
3 Felspar--Potash base Ogun, Kwari, Edo 4 Silica/Flint Lagos, Ogun, Edo 5 Dolomite Kwara 6 Kyanite Kaduna 7 Plaster--moulding Lagos, Edo, Sokoto Source: Irabor et al (1998) S/No Glaze Coating Materials Location 1 Felspar Ogun, Kogi, Edo 2 Quartz Ogun, Kogi, Edo 3 Zinc Oxide Ogun 4 Zircon Plateau 5 Calcium Carbonate Edo, Ogun 6 Barium Carbonate Plateau 7 Colour pigment Import
FIIRO successfully development suitable compositions for the manufacture of porcelain insulators based on felspar, kaolin, quartz, plastic clay and dolomite, while suitable glazes were developed from felspar, kaolin, quartz, barium carbonate, calcium carbonate, zircon, zinc and coloured stain.
He was able to achieve a dense hard, white translucent and glassy effect on his formulated porcelain body at 1300[degrees]C of saggar cone 10 (Kaolin 32%, Ballclay 8%, felspar 48%, Quartz 12%) which yielded the best porcelain property.
Felspars and quartz (silica) are giant grains in the multi plate-like structure of the clay body.
Clay bodies are composed of clay(s), various glass formers such as frits and felspars (depending upon the clay body temperature range) and fillers such as sand, grog and molochite, to achieve a precise handling characteristic, firing range, texture, shrinkage, absorption, colour and glaze compatibility in a specific kiln atmosphere.
Traditionally, porcelain clay body formulas are composed of 50 percent of a single kaolin, 25 percent flint and 25 percent felspar and do not handle well, resulting in a 'flaccid' condition and 'rubbery' feel in forming operations.
Information on felspars
supplied by Tom Landon, Technical Services Leader, Imerys North America Ceramics.
In clay body formulas, felspars form eutectics, bringing clays, flint, talc, pyrophyllite, and other refractory materials into a vitreous state when heated.
In glazes, felspars act as a flux generally above cone 6 which brings other glaze materials into a melt.
is mining MC 200-K and MC 325-K (325 mesh) felspars out of a granite-type rock that formed in the earth's crust as magma and, upon cooling, crystallized into a solid rock body.