With chalk, powder

Powder with metal (e.g. mercury with chalk) used as purgative. 

This consists of zinc oxide in the form of a light, odourless, white powder. It may contain, as impurities, lead carbonate and sulphate and oxides of iron, cadmium and arsenic, and may be adulterated with chalk, barium sulphate and clay (kaolin). Besides the technical tests already described (see General Methods), the following tests and determinations are made. 

An intimate mixture of the ore with chalk and sodium chloride or calcium cliloride, or with calcium chloride alone, is heated to about 600" to 700 C. or the ore may be first fused with sodium hydrogen sulphate, and then with lime or a calcium salt. The residue is powdered and treated witli boiling concentrated hydrochloric acid, wliich decomposes the tungstate with precipitation of tungsten trioxide. 

Precipitated white, heavily chalking powder. Difficult to wet with water. Crystalline flakes with a mother-of-pearl luster, d (14°C) 2.942. At about 800°C, melts to a dark liquid which hardens to an amber-yellow, transparent mass. Soluble in alkali as a thio salt. Can be converted to GeOg by dissolving in ammonia and oxidizing with H3O3. Volatile in an inert atmosphere at 800°C. 

Tertiary butyl peroxy benxoate technically pure liquid 50% powder with chalk Standard type for SMC/BMC at 130-160°C can be accelerated by promoters sensitive to some fillers and pigments (e.g. carbon black). Standard for granulated molding compounds at 130-160°C without accelerator can easily be mixed in as free-flowing powder HI... 

Di(tertiary butylperoxy isopropyl) benzene technically pure flakes Special for granulated molding compounds at 140-170°C without accelerator not sensitive to fillers pigments and promoters also available as 40% powder with chalk hi... 

Medium (art) n. In a general sense, the particular material with which a work of art is executed oils, water color, chalks, lithographic stone, pen and ink, etc. It may also refer to the hquid with which powdering pigments are ground to make artist s paint, and in a more restricted sense, to the liquid used to render such paint more fluid and workable. 

Three graphites (Table I), one natural with a wide size distribution two synthetic with different particle sizes, respectively O.S to 2 microns and 50 to 60 microns, two iron oxides (hematite and magnetite also with wide size spectra) and chalk powder were used in these tests and rubbed against a slab of plywood, and two drawing mats of different roughness. 

A second method is to evaporate down urine to a yrapy consistency, and tlien add pure nitric arid, when mtrate of urea separates out as a cryrinhine powder, which is decomposed on the addition of potassium carbonate, with formaticm of potassium nitrate and free urea. TIrese bodies can then he eamly separated by treatment with alcohol, in W hioh the urea dissolves. A third method is that reconnnended by Berzelius a concentrated solution of oxalic arid is added to the evaporated utin when a precipitate of the insoluble oxalate of urea is thrown down this is boiled with chalk, when the pure urea is left in solution. 

Have been investigated a dust, discriminated with the wettability (a talcum powder the ground, median diameter is equal = 25 microns, white black about SjQ =15 microns solubility in water of 10 % on weight (25 C) and a chalk powder). 

If the polymer is not available as reactor powder and needs pellet grinding, the costs will probably be uneconomic. If reactor powder is used, there may be a risk of its availability being discontinued as happened with PP reactor powder used in an experimental pin barrelled extruder. In this case, a flood fed 20 mm extruder with four pins of 3 mm diameter mounted radially at 90° to each other and at 2 D intervals, passed through slots in the screw flights [6]. Good dispersion was achieved with PP powder with 20 wt% chalk filler blends, whereas dispersions were poor when PP granules were used. Soon afterwards, the reactor producing the PP powder was closed down, and at the time there was no alternative supplier. However, in the production of colour masterbatches, linear low-density polyethylene reactor powder is sometimes used. 

Powder of Mercury with Chalk, B.Vet.C. Tablets of Digitalis, Compound, B.P.C. 

---