Roasting muffle

It is prepared by pasting potassium or sodium dichromate with three times its weight of boric acid, roasting the mixture at 500°C in a muffle furnace in an oxidizing atmosphere, then hydrolyzing the melt with water and superheated steam. The product is then dried and ground. 

Combustion/ Solid fuel-fired furnaces Fuel in direct contact Recuperative Manual and Batch, periodic Natural/self, Crucible, shaft Melting roasting Shaft, muffle... 

A 10 g sample is roasted at 650°C and decomposed with hydrochloric acid/hydrogen peroxide. The Pt and Pd in the solution is pre-concentrated using adsorbent materials which are composed of active charcoal and anion resin. The adsorbent materials are washed sequentially with 2% ammonium bifluoride, 5% hydrochloric acid and distilled water, and subsequently ashed in a muffle furnace at 650°C. The total residue of ca. 0.25 mg is dissolved with 2 ml fresh aqua regia, then diluted to 5ml using 10% hydrochloric solution, and determined using ICP-MS, which has a detection limit of 0.2 ppb for Pt and Pd. The residue can also be mixed with a spectral buffer, and determined by DC-arc ES, which has detection limits of 0.3 ppb for Pt and 0.2 ppb for Pd. 

In a muffle or crucible furnace (Fig. 11a and 6), substances are roasted in crucibles. 

Determining the Equivalent of Lead. Roast a clean porcelain bowl in a muffle furnace at 4C0-450 °C, and after cooling it in a desiccator, weigh it with an accuracy up to 0.01 g. Put about 0.5 g of granulated lead in the bowl and weigh it with the same accuracy. Pour 10 ml of a 40% nitric acid solution onto the metal, cover the bowl with a watch glass, and place it in a water bath. See what happens. Write the equation of the reaction. 

Transfer the bowl into a muffle furnace and roast the precipitate at 400-450 °C during one hour. Cool the bowl with the substance to room temperature in a desiccator and weigh it. Use the found value of the equivalent and the approximate value of the atomic mass of lead to determine its valence. Calculate a more accurate value of the atomic mass of lead from the obtained data, compare your result with the value of the atomic mass of this element given in Mendeleev s periodic table, and establish the magnitude of the error in per cent. 

Preparation and Properties. Spill 5 g of pure boric acid into an iron crucible (better use a platinum crucible why ). Cover the crucible with its lid and roast it in a muffle furnace at 800 °C up to complete removal of the water. What reactions occur To extract the boric acid anhydride, immerse the bottom part of the red-hot crucible into cold water. Transfer the extracted substance into a bottle with a good stopper. 

Processing of Barium Sulphate into Barium Chloride, a. Preparation of Barium Sulphide. Mix 4 g of barium sulphate and 2 g of powdered charcoal, place the mixture into a chamotte or porcelain crucible, and cover the mixture with powdered charcoal. Close the crucible with its lid and roast it strongly (600-700 °C) for an hour in a muffle furnace. Write the equation of the reaction. 

Preparation of Aluminium Sulphate from Kaolin. Roast about 25 g of kaolin with the access of air in a muffle furnace (800 °C) to remove the moisture and oxidize... 

Preparation of Manganese by the Aluminothermic Process. Perform the experiment in the presence of your instructor ) Put 20 g of finely comminuted manganese(IV) oxide into a porcelain crucible and roast it in a muffle or crucible furnace at 800 °G during an hour. What forms Why is manganese(IV) oxide not used directly for producing metallic manganese by the aluminothermic process ... 

Preparation of Tin by Reduction with Charcoal. Prepare a mixture of 2.5 g tin(IV) oxide, 1 g of charcoal, and 0.5 g of ammonium carbonate. Transfer the mixture into a crucible and roast it in a muffle furnace. Write the equation of the reaction. Transfer the obtained bead into another crucible and fuse it with borax. After cooling, break the crucible and wash off the borax with hot water. 

Preparation of Lead. a. Thoroughly mix 5 g of lead(II) oxide and 0.5 g of finely ground charcoal. The lead(II) oxide must be preliminarily dried in a drying cabinet at 100 °C, and the charcoal roasted in an iron crucible covered with a lid. Put the mixture into a porcelain crucible, spill charcoal over it, and roast it in a muffle furnace at 800 °C. After 10 or 15 minutes, mix the contents of the crucible with a carbon rod and again roast them during 30 minutes. Pour out the molten lead onto a chamotte dish. Cool the metal bead and keep it for following experiments. Calculate the yield in per cent. Write the equations of the reactions. 

Preparation of Antimony. Put a thoroughly dried mixture of 12 g of antimony sulphide, 5 g of reduced powdered iron, 1.5 g of sodium sulphide, and 0.5 g of powdered charcoal into a chamotte or porcelain crucible and roast it in a muffle furnace at 800 °C. After the entire mixture softens, continue the heating for another 20-30 minutes. Next cool the crucible, break it, and extract the antimony bead. 

The formation of the chlorides is effected in the dry way by calcination with sodium chloride or in the wet way by interaction with ferrous chloride and hydrochloric acid or with ferric chloride. The wet way is only adopted if fuel is scarce, or the escape of noxious vapours into the atmosphere is not permissible. In the dry method the ore is oxidized by a preliminary roasting, and then chloridized by calcination with sodium chloride or Abraum salts in a furnace of the reverberatory or muffle type, the principal product being cupric chloride. The Dotsch modification of the wet process, worked at Rio Tinto, depends on the action of ferric-chloride solution on a mixture of the ore with sodium sulphate and ferric chloride. The liquid drawn off from the bottom of the heaps of ore contains cuprous chloride in solution as a complex salt. The copper is liberated by the action of iron, the ferrous chloride simultaneously formed being chlorinated in towers to ferric chloride, and the product employed for moistening the heaps of ore. 

Anhydrous sodium sulphate (BDH Analar grade or equivalent) was roasted in a muffle furnace at 650°C, cooled and stored in a vacuum dessicator. Reagent grade Florisrl was activated at 650 °C in a muffle furnace, cooled and stored in a vacuum dessicator. Before use, it was deactivated with deionised water (8. 5% v/v) and mixed for 1 hour in a stoppered glass bottle on a ball-mill roller. 

Roasting Ga with a rare-earth metal in a muffle furnace at ca. 750 °C gives gallates with the garnet structure M3Ga60x2 (M = Y, Gd, or Dy). ... 

In the roasting experiment each material sample weighed 50g, roasting time was 90 minutes, the maximum temperature was 900 ° C. Each carbon amount selects 4%, 8%, 12% and 16% of the ore then install them in the crucible into the muffle furnace to determine the optimum carbon content. 

Herreshoff Furnace. A multiple-hearth cylindrical muffle roasting furnace such a furnace has been used to calcine of fireclay. 

Terry (1893) gives methods for producing the red iron oxide pigment, copperas red, from either soiuce [natural copperas] is an acid sulphate of iron, which is leached out and neutralised by addition of iron in the form of scrap. The neutral sulphate is crystalhsed out of the liquor, and calcined in a muffle furnace, the shade of the ultimate product being governed by the degree of duration of the roasting. Alternatively, waste-product copperas was neutralised by the addition of scrap iron and hme was added to throw down the iron as oxide the material was then calcined. 

Prepare a 0.1 M solution of iron(III) chloride acidified with nitric acid. By the slow addition of ammonia to the boiling solution, as in Sec. 13.3.4, precipitate the hydroxide or hydrous oxide, wash thoroughly and dry at 110 C. Then roast at 550 C in a muffle furnace. Grind a portion to a very fine powder and submit to XRD and compare the pattern with that of a-Fe203. Obtain a thermogravimetric curve for the llO C dried powder. Carry out a BET surface area determination on the final product. 

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