Ferrous sulfate crystals

When the aqueous solution was cooled to room temperature, ferrous sulfate crystallized until the aqueous solution concentration decreased to about 113 g/L. The precipitated product was relatively pure, as indicated by comparing the chemical analyses, shown in Table in, of the initial solution and the solid ferrous sulfate crystals. The distribution coefficient between the aqueous and solid phases for the impurities is also very favorable. 

Procedure. A crystal of ferrous sulfate (pin head) is placed on a spot plate together with a drop of the test solution. A drop of concentrated sulfuric acid is allowed to run in at the side. In the presence of nitrate, a brown ring is formed around the ferrous sulfate crystal. 

The mother Hquor from the cmde ferrous sulfate crystallisation contains neady all the chromium. It is clarified and aged with agitation at 30°C for a considerable period to reverse the reactions of the conditioning step. Hydrolysis reactions are being reversed therefore, the pH increases. Also, sulfate ions are released from complexes and the chromium is converted largely to the hexaaquo ion. Ammonium chrome alum then precipitates as a fine crystal slurry. It is filtered and washed and the filtrate sent to the leach circuit the chrome alum is dissolved in hot water, and the solution is used as cell feed. 

Silver [7440-22-4]—The coloi additive silvei (EEC No. E 174) is a crystaUine powdei of high purity silver prepared by die reaction of silver nitrate with ferrous sulfate in the presence of nitric, phosphoric, and sulfuric acids. Poly(vinyl alcohol) is used to prevent the agglomeration of crystals and the formation of amorphous silver. 

Ammonium ferrous sulfate (6H2O) [7783-85-9 (6H20) 10045-89-3 (anhydr)] M 392.1, m 100 (dec), d 1.86. A soln in warm water (l.5mL/g) was cooled rapidly to 0 , and the resulting fine crystals were filtered at the pump, washed with cold distilled water and pressed between sheets of filter paper to dry. 

Ferric sulfate (XH2O) [10028-22-5] M 399.9 + XH2O. Dissolve in the minimum volume of dilute aqueous H2SO4 and allow to evaporate at room temp until crystals start to form. Do not concentrate by boiling off the H2O as basic salts will be formed. Various hydrates are formed the—common ones are the dodeca and none hydrates which are violet in colour. The anhydrous salt is colourless and very hygroscopic but dissolves in H2O slowly unless ferrous sulfate is added. 

The crystallization of ferrous sulfate as heptahydrate is commonly used today. The concentration of iron in the acid bath is approximately 80g/L as Fe3+. The crystallization of FeS04 7H20 is achieved by cooling the acid waters in heat exchangers or evaporation under vacuum after pickling. 

Both sulfuric and hydrochloric acids are used commonly for cleaning steel. Sulfuric acid can be regenerated by crystallizing ferrous sulfate. Hydrochloric acid can be recovered by distilling off the... 

Sulfuric acid can be regenerated by crystallizing ferrous sulfate. 

F-S [Ferrous sulfate] A process for removing ammonia, hydrogen sulfide, and hydrogen cyanide from coke-oven gas by scrubbing with aqueous ferrous sulfate solution obtained from steel pickling. A complex series of reactions in various parts of the absorption tower yield ammonium sulfate crystals and hydrogen sulfide (for conversion to sulfur or sulfuric acid) as the end products. Developed in Germany by F. J. Collin A.G. 

Penniman-Zoph A process for making a yellow iron oxide pigment. Hydrated ferric oxide seed is added to a solution of ferrous sulfate and the suspension circulated over scrap iron, with air being passed through. Hydrated ferric oxide deposits on the seed crystals, giving a finely divided, yellow pigment ... 

FeTi03 + 2H2S04 = TiOS04 + FeS04 + 2H20 Much of the ferrous sulfate is crystallized out and discarded. The titanium is hydrolyzed by boiling, yielding hydrated titanium dioxide, which is then calcined ... 

Also known as black iron oxide iron monoxide. fer as ak.sTd ferrous sulfate inorgchem FeS04-7H20 Blue-green, water-soluble, monoclinic crystals used as a mordant in dyeing wool, in the manufacture of ink, and as a disinfectant. Also known as copperas ferrisulphas green copperas green vitriol iron sulfate. fer as sal,fat ... 

Dissolve 500 g. of commercial copper sulfate (blue-stone) in 1.5 1. of boiling water in an evaporating dish, add 3 g. of ferrous sulfate (unless this is known to be present as an impurity), and allow the solution to cool. Select about 1 g. of the crystals that form and test them for iron. To do this, dissolve the material in 10 cc. of water, add about 2 cc. of concentrated nitric acid, and boil for a few minutes. Cool the solution and add... 

Drain the crystals of copper sulfate that have by this time accumulated in the original solution, if necessary evaporating the mother liquors from them to secure a second crop of crystals. Secure about half of the original material in this form and set aside the mother liquor for future use. Recrystallize the salt as in the original procedure, using a proportionate quantity of water. Again test a specimen of the crystals obtained for iron and convince yourself that it is still present. Those experiments show that the ferrous sulfate is not removed by several crystallizations. 

As a preliminary, ferric sulfate is made by the oxidation of ferrous sulfate. Dissolve 100 g. of ferrous sulfate in 100 cc. of boiling water, to which has been added before heating 10 cc. of sulfuric acid. Add concentrated nitric acid portionwise to the hot solution, until a diluted sample gives a reddish-brown (not black) precipitate with ammonia. This will require about 25 cc. Boil the solution down to a viscous liquid to get rid of excess nitric acid, dilute to about 400 cc., and add the calculated weight of ammonium sulfate. The crystallization is conducted as in the former exercise, preferably under 20°. By the addition of potassium sulfate, the corresponding potassium iron alum may be secured. In this case, it is necessary to concentrate the solution until there is about four parts of water to one of the hydrated alum and cool to about zero to secure crystallization. Both of these alums are amethyst in color, the potassium salt being much less stable and having a rather low transition point. 

Put 20 g. of potassium ferrocyanide in a 250-cc. Erlenmeyer flask, adding 30 cc. of water. Place the flask on the water bath and heat till the ferrocyanide dissolves. Add 35 cc. of nitric acid (sp. gr., 1.24) and continue heating until a test portion shows no blue color but a dark green precipitate when treated with ferrous sulfate. Let stand for a day or two and filter off the tarry impurities. Now neutralize with sodium carbonate, taking care that no excess is added. Warm and, when cool, add from one to two times the volume of alcohol (ethyl). Set the flask in a dry place for a day or two, after which the impurities (chiefly crystals of potassium nitrate) may be filtered off, and the nitro-prusside crystallized out. Sometimes two or three treatments with alcohol are necessary. In order to expedite the operation of evaporating down to crystallization, the solution may be evaporated by heating in a suction flask under reduced pressure. Quick crystallization increases the yield. The yield should be above 75 per cent. 

Use of a Cooling or Evaporative Crystallizer. The crystallizer is necessary in order to recover ferrous sulfate from spent sulfuric acid baths. For facilities employing hydrochloric acid, proven commercial processes can be employed to recover iron and hydrochloric acid. 

DISSOLVE A SMALL CRYSTAL OF IRON SULFATE (FERROUS SULFATE, FeSO ) IN HALF A TEST TUBE FULL OF WATER. 

DOUBLE SALT. A hydrated compound resulting from crystallization ol a mixture of ions in aqueous solution. Common examples arc the alums, made by ciystallizing from solution either potassium or ammonium sulfate and aluminum sulfate Rochelle salt (potassium sodium tartrate), made from a water solution of potassium acid tartrate treated with sodium carbonate and Mohr s salt (fertous ammonium sulfate), crystallized Iruin mixed solutions of ferrous sulfate and ammonium sulfate. 

To a solution of ferrous sulfate heptahydrate in of hot water is added a solution of 2-(2-carboxy-4-chloro-6-nitrophenoxy)acetic acid and aqueous concentrated ammonia solution in water under stirring. After stirring, to the reaction mixture is twice added aqueous concentrated ammonia solution. While the reaction mixture becomes exothermic, stirring is continued. The resultant mixture is filtered through a celite layer under reduced pressure and washed with hot water twice. The filtrate is cooled and made acid with concentrated hydrochloric acid. The precipitated crystals are washed with water and dried to give 6-chloro-3,4-dihydro-3-oxo-2H-l,4-benzoxazine-8-carboxylic acid. 

In subsequent experiments, using other crystal systems, such as ferrous sulfate and sodium hydrogen phosphate, it was similarly observed that the first crystallization product to form was the one most closely resembling the structure of the solvent (Nyvlt, 1995). For the case of citric acid, this is the monohydrate, which more closely resembles the aqueous structure. As the temperature of the solution is increased, the structure of the solvent, as well as the solubility of the crystal, changes, resulting in a more thermodynamically stable anhydrous product. This conversion between the kinetic and thermodynamic product occurs at a critical transition temperature, below which the structure of the solution favors the formation of the hydrated product. As the transition temperature is surpassed, the anhydrous product becomes favored. 

Ferrous Sulfate occurs as pale, blue-green crystals or granules that are efflorescent in dry air. In moist air, it oxidizes readily to form a brown-yellow, basic ferric sulfate. A 1 10 aqueous solution has a PH of about 3.7. One gram dissolves in 1.5... 

Ferrous Sulfate TS Dissolve 8 g of clear crystals of ferrous sulfate (FeS04-7H20) in about 100 mL of recently boiled and thoroughly cooled water. Prepare this solution fresh. 

Orthophenanthroline TS Dissolve 150 mg of orthophen-anthroline (C12H8N2-H20) in 10 mL of a solution of ferrous sulfate, prepared by dissolving 700 mg of clear crystals of ferrous sulfate (FeS04-7H20) in 100 mL of water. The ferrous sulfate solution must be prepared immediately before dissolving the orthophenanthroline. Store the solution in well-closed containers. 

These green crystals can be purified by recrystallization from rain water into very glassy, transparent crystals of ferrous sulfate (FeS04 - 7H20). In fact, the name vitriol derives from the Latin vitrum, meaning glass. 

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