Ferric sulfates

METHOD 1 [112l-5g phenol in dH20 is stirred 5 hours at 20 C with some ferric sulfate (Fe2(S04)3, an additional 7mLs dH20, 13mLs 6% H2O2 and a pinch of aluminum oxide (AI2O3). Yield of catechol is 2.5g (50%). 

Bertrand s reagents (glucose estimation) a) 40 g of copper sulfate diluted to 1 liter (fc) rochelle salt 200 g, NaOH 150 g, and sufficient water to make 1 liter (c) ferric sulfate 50 g, H2SO4 200 g, and sufficient water to make 1 liter d) KMn04 5 g and sufficient water to make 1 liter. 

Thus, at a concentration of 0.95 g Na2S /100 g solution, the solubihty of mercuric sulfide has increased to 2100 ppm. It is customary to use no greater than a 20% excess of the alkah sulfide. Because the particle size of the precipitated mercuric sulfide is so small, it is helpful to add a ferric compound such as ferric chloride or ferric sulfate to effect flocculation. Sometimes other flocculating agents (qv) may also be added, eg, starch or gum arabic. 

Oxidi ng Solutions. In many leaching processes the mineral must be oxidized, as for instance, in the leaching of copper sulfides by ferric sulfate or ferric chloride solutions. 

NKK s Bio-SR process is another iron-based redox process which instead of chelates, uses Thiobacillusferroidans )2iQ. - 2i to regenerate the solution (9). This process absorbs hydrogen sulfide from a gas stream into a ferric sulfate solution. The solution reacts with the hydrogen sulfide to produce elemental sulfur and ferrous sulfate. The sulfur is separated via mechanical means, such as filtering. The solution is regenerated to the active ferric form by the bacteria. 

The amount of sludge produced duriag clarification can be reduced by 50—90% the approximate dry weights of soHds removed per pound of dry alum and ferric sulfate are approximately 0.11 and 0.23 kg, respectively. 

The metal salts reduce the alkalinity in the water therefore, it may be necessary to add base in the form of lime or soda ash. One part of technical aluminum sulfate (AI2 (804)3-141120) reduces the alkalinity as CaCO by 0.55 parts and one part of technical ferric sulfate, Fe2 (SO4 )3-H2 0, by 0.68 parts. The reaction is... 

Ferric sulfate (commercial product Fe2 (8O4 )3-H20) contains a minimum of 20 wt % iron(lll). It is available only as a soHd, which must be dissolved immediately before use. The solution must be kept concentrated to avoid premature hydrolysis and precipitation of Fe(OH)2. Such concentrated solutions have low pH values and, thus, prevent hydrolysis but are very corrosive. Containers must therefore be coated with or be constmcted of corrosion-proof materials. 

Color can be removed effectively and economically with either alum or ferric sulfate at pH values of 5—6 and 3—4, respectively. The reaction is stoichiometric and is a specific reaction of the coagulant with the color to form an insoluble compound (17). The dosage required may be as high as 100—150 mg/L (380—570 mg/gal). Raw-water colors may be as high as 450—500 units on the APHA color scale. The secondary MCL (maximum contaminant level) for color in the finished water is 15 units, although most municipal treatment plants produce water that seldom exceeds 5 units. 

The foHowing factors are important in dump leaching (/) the role of bacteria (2) the appHcation of acid to prevent or delay precipitation of hydrated ferric sulfate (J) oxidation to remove excess iron from mine water in settling pools, as shown in equations 38 and 39 (4) optimization of dump configuration for good solution distribution and (5) avaHabHity of oxygen. 

If the solution is acidified and aUtde ferric sulfate added, ferric ferrocyanide [14038-43-8], Fe4[Fe(CN)g]2, is produced. This salt has a characteristic deep blue color, and the reaction may be used to test for the cyanide. 

Eor the cover-coat direct-on process, a ferric sulfate [10028-22-5] Ee2(S0 2> etch is included in the metal pretreatment for rapid metal removal. It is designed to remove ca 20 g/m (2 g/ft ) of iron from the sheet metal surface. Hydrogen peroxide [7722-84-1/, H2O2, is added intermittently to a 1% ferric sulfate solution to reoxidize ferrous sulfate [7720-78-7] EeSO, to ferric sulfate. 

TABLE 2-52 [Fe,(S04)3] Ferric Sulfate TABLE 2-53 [FeCNOala] Ferric Nitrate TABLE 2-58 Hydrogen Fluoride (HF) TABLE 2-59 Hydrogen Peroxide (H O ) ... 

Ammonium ferric sulfate (I2H2O) [7783-83-7 (12H20), lOI38-04-2 (anhydr)] M 482.2, m -37 , d 1.71. Crystd from aqueous ethanol. 

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. 

A more recent process, the P2 etch [60], which uses ferric sulfate as an oxidizer in place of sodium dichromate avoids the use of toxic chromates, but still provides a similar oxide surface morphology (Fig. 15) allowing a mechanically interlocked interface and strong bonding [9]. The P2 treatment has wide process parameter windows over a broad range of time-temperature-solution concentration conditions and mechanical testing confirms that P2-prepared surfaces are, at a minimum, equivalent to FPL-prepared specimens and only slightly inferior to PAA-prepared surfaces [61]. 

Ferric sulfate is shipped in car and truck load lots of 50 lb and 100 lb moisture-proof paper bags and 200 lb and 400 lb fiber drums. 

General precautions should be observed when handling ferric sulfate, such as wearing goggles and dust masks, and areas of the body that come in contact with the dust or vapor should be washed promptly. 

Aeration of ferric sulfate should be held to a minimum because of the hygroscopic nature of the material, particularly in damp atmospheres. Mixing of ferric sulfate and quicklime in conveying and dust vent systems should be avoided as caking and excessive heating can result. The presence of ferric sulfate and lime in combination has been known to destroy cloth bags in pneumatic unloading devices. Because ferric sulfate in the presence of moisture will stain, precautions similar to those discussed for ferric chloride should be observed. 

Ferric sulfate is usually stored in the dry state either in the shipping bags or in bulk in concrete or steel bins. Bulk storage bins should be as fight as possible to avoid moisture absorption, but dust collector vents are permissible and desirable. Hoppers on bulk storage bins should have a minimum slope of 36 however, a greater angle is preferred. 

Bins may be located inside or outside and the material transferred by bucket elevator, screw, or air conveyors. Ferric sulfate stored in bins usually absorbs some moisture and forms a thin protective crust which retards further absorption until the crust is broken. 

Feed solutions are usually made up at a water to chemical ratio of 2 1 to 8 1 (on a weight basis) with the usual ratio being 4 1 with a 20-minute detention time. Care must be taken not to dilute ferric sulfate solutions to less than 1 percent to prevent hydrolysis and deposition of ferric hydroxide. Ferric sulfate is actively corrosive in solution, and dissolving and transporting equipment should be fabricated of type 316 stainless steel, rubber, plastics, ceramics, or lead. 

Coagulation involves the addition of chemicals to alter the physical state of dissolved and suspended solids. This facilitates their removal by sedimentation and filtration. The most common primary coagulants are alum ferric sulfate and ferric chloride. Additional chemicals that may be added to enhance coagulation include activate silica, a complex silicate made from sodium silicate, and charged organic molecules called polyelectrolytes, which include large-molecular-weight polyacrylamides, dimethyl-diallylammonium chloride, polyamines, and starch. 

In sedimentation the water to be treated flows slowly through a tank, allowing the suspended material in the water to fall to the base of the tank. The use of coagulating compounds, such as aluminum and ferric sulfate, increases the efficiency. 

Eisenoxyd-salz, n. ferric salt, iron(lll) salt, -sulfat, n. ferric sulfate, iron(IIl) sulfate. 

Feiri-. ferric, ferri-, iron(III). -acetat, n. ferric acetate, iron(IIl) acetate, -ammonsulfat, n. ammonium ferric sulfate, -bromid, n. ferric bromide, iron(III) bromide, -chlorid, n. ferric chloride, iron(lll) chloride, -chlor-wasserstoff, -chlorwasserstoffsMure, /. fer-richloric acid. -cyan, n. ferricyanogen. -cyaneisen, n. ferrous ferricyanide (Turn-bull s blue), -cyanid, n. ferric cyanide, iron(III) cyanide ferricyanide. 

Ferric Sulfate (P errisul) Ferrous or Feme. . . Ferrous Sul/aie. 

Ferric Picrate. [C6H2(N02)3 0]3Fe.llH20, mw 938.4, N 13.44%, yellowish-red needles. Was prepd in 1911 by Kast by treating a hot satd soln of ferric sulfate with Ba picrate (Ref 1). Hopper (Ref 2) prepd several hydrated ferric pic rates of unknown w content which expld at 295. Their impact sensitivity ranged from 6 (for material dried at 150°), to 36" (for material dried at 25°) (PicArsn app with 2kg wt)... 

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