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Ammonium aluminium sulfate = Ammonium alum sulfate = Tschermigite
CAS Number : 7784-25-0 / 7784-26-1
EC Number : 232-055-3 616-522-2
Ammonium aluminium sulfate, also known as ammonium alum or just alum (though there are many different substances also called "alum"), is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2·12H2O.
Ammonium aluminium sulfate is used in small amounts in a variety of niche applications.
The dodecahydrate occurs naturally as the rare mineral tschermigite.
Production and basic properties
Ammonium alum is made from aluminium hydroxide, sulfuric acid and ammonium sulfate.
Ammonium aluminium sulfate forms a solid solution with potassium alum.
Pyrolysis leaves alumina.
Such alumina is used in the production of grinding powders and as precursors to synthetic gems.
Uses
Ammonium alum is not a major industrial chemical or a particularly useful laboratory reagent, but it is cheap and effective, which invites many niche applications.
Ammonium aluminium sulfate is used in water purification, in vegetable glues, in porcelain cements, in deodorants and in tanning, dyeing and in fireproofing textiles.
The pH of the solution resulting from the topical application of ammonium alum with perspiration is typically in the slightly acid range, from 3 to 5.
Ammonium alum is a common ingredient in animal repellant sprays.
Names
Other names
Ammonium alum sulfate
Tschermigite
Identifiers
CAS Number : 7784-25-0
7784-26-1 (dodecahydrate)
ChemSpider : 2297489
56419 (dodecahydrate)
ECHA InfoCard: 100.029.141
EC Number : 232-055-3 616-522-2 (dodecahydrate)
E number : E523 (acidity regulators, ...)
KEGG : D02842 (dodecahydrate)
PubChem CID: 3032540
62668 (dodecahydrate)
RTECS number : WS5640010
UNII : DPU64XYB1D
5C36DRL9ZN (dodecahydrate) check
CompTox Dashboard (EPA) : DTXSID7051428
Properties
Chemical formula: (NH4)Al(SO4)2
Molar mass :237.15 g/mol (anhydrous)
453.33 g/mol (dodecahydrate)
Appearance :white crystals
Density :2.45 g/cm3 (anhydrous)
1.64 g/cm3 (dodecahydrate)
Melting point: 93.5 °C (200.3 °F; 366.6 K) (dodecahydrate)
Boiling point: 120 °C (248 °F; 393 K) dehydr. (dodecahydrate)
Solubility in water :15 g/100 ml (20 °C, dodecahydrate)
Structure
Crystal structure :Hexagonal (anhydrous)
Cubic (dodecahydrate)
Coordination geometry: Octahedral (Al3+)
Hazards
GHS labelling:
Pictograms :Skin Irrit. 2; Eye Irrit. 2
Signal word :Warning
Hazard statements :H315, H319
Precautionary statements : P264, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362
What Is Ammonium aluminium sulfate?
The chemical compound ammonium sulfate is primarily used in fertilizers but is important in other industries as well.
While it isn’t considered highly hazardous to humans, there are some important precautions to take if you’re using it.
Chemical Properties
Ammonium sulfate, also called diammonium sulfate or sulfuric acid diammonium salt, is a white crystalline solid with no smell.
Ammonium aluminium sulfate tastes salty.
The compound dissolves easily in water but will not dissolve in alcohol or acetone.
Ammonium aluminium sulfate readily absorbs water, so if it’s exposed to moist air, it will “scab” on the damp surfaces.
Ammonium aluminium sulfate chemical formula for ammonium sulfate is (NH₄)₂SO₄.
When ammonium sulfate reacts with alkaline substances, it gives off ammonia gas.
Finally, ammonium sulfate is a fertilizer that’s sometimes used in making homemade explosives.
Use in Fertilizers
Ammonium sulfate is used most commonly as an artificial fertilizer for alkaline soils.
When introduced into damp soil, an ammonium ion is released.
This creates a small amount of acid, which lowers the pH balance of the soil.
Ammonium aluminium sulfate also contributes nitrogen, which aids in plant growth.
Ammonium aluminium sulfate dissolves relatively slowly, which makes it cheaper than some other artificial fertilizers.
Ammonium sulfate is also used as an herbicide because it will burn the leaves of plants and either kill them outright or at least weaken them for easy removal.
Other Uses
This compound is used in the production of printed circuit boards.
Ammonium aluminium sulfate also in flame retardant materials because it lowers the combustion temperature and increases the production of residues or chars.
Ammonium sulfate activates yeast, so it helps to get industrially produced bread to rise, and it’s also a general-purpose food additive.
Finally, it plays an important role in developing vaccines during the purification process.
The DTap vaccine, which protects children from diphtheria, tetanus, and whooping cough, uses ammonium sulfate for this purpose.
Sulfate AmmoniumHazards of Use
Ammonium sulfate is potentially dangerous to both people and the environment, so it requires care in its use.
Ammonium aluminium sulfate can cause severe irritation and inflammation of the respiratory tract if inhaled.
Eating or drinking ammonium sulfate will cause irritation in the gastrointestinal tract like nausea, vomiting, and diarrhea, although it isn’t toxic unless consumed in large quantities.
Contact with the skin or eyes will cause irritation, redness, itching, and pain.
Ammonium aluminium sulfate may also be a neurotoxin, meaning it can cause confusion and behavioral changes.
Avoiding Exposure
As with any potentially toxic chemical, it’s important to take safety precautions when using ammonium sulfate.
Use ammonium sulfate only in a well-ventilated area or with a personal respirator.
Wear chemical safety goggles and/or a full face safety shield if dusting or splashing solutions is possible.
Also, wearing boots, gloves, and an apron or coveralls made of an impervious material like PVC will prevent skin contact.
Any work area should be outfitted with an eyewash station and emergency shower in case of accidental exposure.
While ammonium sulfate is used as a fertilizer and therefore is readily available, it should not be used lightly.
Taking basic precautions will allow you to get the benefits of using ammonium sulfate without putting yourself at risk.
Sulfate Ammonium FormulaFormula for Ammonium Sulfate:
(NH4)2SO4
Properties for Ammonium Sulfate
Molar mass: 132.14 g/mol
Density: 1.769 g/cm3 (20 °C)
Melting point: 235 to 280 °C (455 to 536 °F; 508 to 553 K) (decomposes)
Synonym(s):Mascagnite
Linear Formula:(NH4)2SO4
CAS Number:7783-20-2
Molecular Weight:132.14
MDL number:MFCD00003391
EC Index Number:231-984-1
Solubilities of NH4Al(SO4)2·12H2O in mixed aqueous solutions of Al2(SO4)3 and (NH4)2SO4 were determined at (25, 30, 40, and 50) °C.
At the same temperatures, solubilities of NH4Al(SO4)2·12H2O in the (NH4)2SO4 + Al2(SO4)3 + H2SO4 + H2O system and densities of the equilibrium solutions were measured for sulfuric acid mass fraction on the salt-free basis, w‘, equal to 0.1.
Ammonium aluminium sulfate measured solubilities were compared with available literature data.
Ammonium alum solubilities are only moderately influenced by the sulfuric acid addition up to w‘(H2SO4) = 0.1.
Ammonium aluminium sulfate addition of sulfuric acid to the ternary (NH4)2SO4 + Al2(SO4)3 + H2O solution increases the ammonium alum solubility in solutions with a NH4/Al molar ratio close to 1.
In contrast, at either low or high NH4/Al molar ratios, the ammonium alum solubility is suppressed by the sulfuric acid addition.
Quality Level: 200
agency: meets USP/NF
vapor pressure: <1 Pa ( 25 °C)
assay: ≥99.0%
form: crystals
ign. residue: ≤0.005%
color :white
pH: 5 (100 g/L in H2O)
mp: >280 °C (dec.) (lit.)
solubility: 754-764 g/L
density : 1.77 g/mL at 25 °C (lit.)
anion traces: chloride (Cl-): ≤5 ppm
nitrate (NO3-): ≤0.001%
phosphate (PO43-): ≤5 ppm
cation traces: Fe: ≤ 5 ppm
heavy metals: ≤ 5 ppm
shipped in: ambient
storage temp.: room temp
SMILES string: N.N.OS(O)(=O)=O
InChI: 1S/2H3N.H2O4S/c;;1-5(2,3)4/h2*1H3;(H2,1,2,3,4)
InChI key: BFNBIHQBYMNNAN-UHFFFAOYSA-N
Ammonium aluminium sulfate, also known as ammonium alum or just alum, is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2·12H2O.
Ammonium aluminium sulfate is used in small amounts in a variety of niche applications.
Aluminium Ammonium Sulphate Dodecahydrate Ammonium aluminium sulfate, also known as ammonium alum or just alum, is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2-12H2O.
Ammonium aluminium sulfate is used in small amounts in a variety of niche applications.
The dodecahydrate occurs naturally as the rare mineral tschermigite.
CAS Number: 7784-26-1
Formula Weight: 453.33
Formula: AlNH4(SO4)2·12H2O
Hazard Info: Toxic
Density (g/mL): 1.645
Freezing Point (°C): 94.5
Solubility: Water and Glycerol
Synonyms: Ammonium Alum, Aluminum Ammonium Sulfate Dodecahydrate
Shelf Life (months): 36
Storage: Green
alum, any of a group of hydrated double salts, usually consisting of aluminum sulfate, water of hydration, and the sulfate of another element.
Ammonium aluminium sulfate whole series of hydrated double salts results from the hydration of the sulfate of a singly charged cation (e.g., K+) and the sulfate of any one of a number of triply charged cations (e.g., Al3+).
Aluminum sulfate can thus form alums with sulfates of the singly charged cations of potassium, sodium, ammonium, cesium, and other elements and compounds.
In similar fashion, sulfates of the triply charged cations of iron, chromium, manganese, cobalt, and other metals may take the place of aluminum sulfate.
The most important alums are potassium aluminum sulfate, ammonium aluminum sulfate, and sodium aluminum sulfate.
Potassium aluminum sulfate, also known as potassium alum or potash alum, has a molecular formula of K2(SO4)·Al2(SO4)3·24H2O or KAl(SO4)2·12H2O.
Alums can easily be produced by precipitation from an aqueous solution.
In producing potassium alum, for example, aluminum sulfate and potassium sulfate are dissolved in water, and then upon evaporation the alum crystallizes out of the solution.
A more common production method is to treat bauxite ore with sulfuric acid and then with potassium sulfate.
Ammonium alum is produced by the evaporation of a water solution containing ammonium sulfate and aluminum sulfate.
Ammonium aluminium sulfate can also be obtained by treating a mixture of aluminum sulfate and sulfuric acid with ammonia.
Alums occur naturally in various minerals.
Potassium alum, for example, is found in the minerals kalinite, alunite, and leucite, which can be treated with sulfuric acid to obtain crystals of the alum.
Most alums have an astringent and acid taste.
They are colourless, odourless, and exist as a white crystalline powder.
Alums are generally soluble in hot water, and they can be readily precipitated from aqueous solutions to form large octahedral crystals.
Alums have many uses, but they have been partly supplanted by aluminum sulfate itself, which is easily obtainable by treating bauxite ore with sulfuric acid.
Ammonium aluminium sulfate commercial uses of alums mainly stem from the hydrolysis of the aluminum ions, which results in the precipitation of aluminum hydroxide.
This chemical has various industrial uses.
Paper is sized, for example, by depositing aluminum hydroxide in the interstices of the cellulose fibres.
Aluminum hydroxide adsorbs suspended particles from water and is thus a useful flocculating agent in water-purification plants.
When used as a mordant (binder) in dyeing, it fixes dye to cotton and other fabrics, rendering the dye insoluble.
Alums are also used in pickling, in baking powder, in fire extinguishers, and as astringents in medicine.
By means of the thermogravimetric method, differential thermal analysis.
X-ray diffraction phase analysis, infrared spectroscopy, electron microscopy and chemical analyses, stages of decomposition of basic aluminium ammonium sulphate (BAAS) in an environment of carbon and water vapour were studied.
Ammonium aluminium sulfate has been found that the addition of carbon and water vapour influences the course of alunite decomposition only in the last stage, i.e. the desulphuration of the compound.
Ammonium aluminium sulfateThis process occurs at a lower temperature than in air.
Ammonium aluminium sulfate final product of decomposition of the basic salt at 1223 K is γ-Al2O3.
The experimental work was preceded by the thermodynamic analysis of the desulphuration process of BAAS in an environment of carbon and water vapour, and the results have been correlated with experimental data.
Description
Ammonium aluminum sulfate, NH4AI(S04)2·12H2O, is colorless, odorlesswater-soluble crystals.
Also known as ammonium alum,aluminumammonium sulfate,it is used in manufacturing medicines and baking powder, and in dyeing,tanning,andpapermaking.
Chemical Properties
Colorless crystals; odorless; strong astringent taste.
Soluble in water and glycerol; insoluble in alcohol.
Uses
Aluminum Ammonium Sulfate is a general purpose food additive that functions as a buffer and neutralizing agent. its solubility is 1 g in 7 ml of water at 25°c and 1 g in 0.3 ml of boiling water.
Ammonium aluminium sulfate is used in baking powders.
Safety Profile
Irritating if inhaled or ingested. Upon decomposition it emits toxic fumes of NOx and SOx,.
Food Safety Commission of Japan (FSCJ) conducted a risk assessment of aluminium ammonium sulfate and aluminium potassium sulfate.
Ammonium aluminium sulfate evaluation was requested from Ministry of Health, Labour and Welfare (MHLW) to revise the standards for use of additives.
Aluminium ammonium sulfate and aluminium potassium sulfate as additives are assumed reasonably to behave as ions after dissociation, such as aluminium, ammonium, potassium, and sulfate ions, in digestive tract prior to their absorption.
Ammonium aluminium sulfate, also known as ammonium alum or just alum (though there are many different substances also called "alum"), is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2·12H2O. It is used in small amounts in a variety of niche applications.
Ammonium aluminium sulfate dodecahydrate occurs naturally as the rare mineral tschermigite.
Ammonium alum is made from aluminium hydroxide, sulfuric acid and ammonium sulfate.
Ammonium aluminium sulfateIt forms a solid solution with potassium alum.
Pyrolysis leaves alumina. Such alumina is used in the production of grinding powders and as precursors to synthetic gems.
Ammonium alum is not a major industrial chemical or a particularly useful laboratory reagent, but it is cheap and effective, which invites many niche applications.
Ammonium aluminium sulfate is used in water purification, in vegetable glues, in porcelain cements, in deodorants and in tanning, dyeing and in fireproofing textiles.
The pH of the solution resulting from the topical application of ammonium alum with perspiration is typically in the slightly acid range, from 3 to 5.
Ammonium alum is a common ingredient in animal repellant sprays.
Production | Uses | Safety
Ammonium alum, also known as ammonium aluminum sulfate or aluminum ammonium sulfate, with the chemical formula NH4AI(SO4)2 and usually encountered as the dodecahydrate form NH4AI(SO4)2·12H2O.
When used in food, it has the European food additive number E523.
When compared with another two common alums, it is used less in baking powder than sodium aluminum sulfate, and less common than potassium aluminum sulfate in deodorant.
How is Ammonium alum Made?
Different with potassium alum, which has natural and synthetic forms, aluminum alum occurs as a rare mineral in nature and is commercially produced by reacting ammonium sulfate solution with aluminum sulfate solution.
The following is the chemical reaction equation: Al2(SO4)3+(NH4)2SO4+24H2O→2(NH4)Al(SO4)2·12H2O.
Ammonium aluminium sulfate dehydrates at about 250°C to produce aluminum ammonium sulfate anhydrous.
The aluminum sulfate comes from treating minerals bauxite ore (the main component aluminium oxide) with sulfuric acid.
Here is the chemical reaction equation: Al2O3 + 3H2SO4 =Al2(SO4 )3 + 3H2O
And ammonium sulphate can be obtained by the reaction between aluminum sulfate and ammonium. Al2(SO4)3+ 6NH3·H2O→2Al(OH)3+3(NH4)2SO4
Property
Other names Ammonia alum
CAS number 7784-26-1
Chemical formula NH4Al(SO4)2 (anhydrous), NH4Al(SO4)2·12H2O (dodecahydrate)
Molecular weight 453.32 (dodecahydrate)
Appearance
Large, colourless crystals or white powder with astringent taste.
Solubility
Freely soluble in water, soluble in ethanol.
What’re the Uses of Ammonium alum?
Ammonium alum is used almost for the same purposes as soda alum and potassium alum.
Ammonium aluminium sulfate can be used as a leavening acid in baking powder, as a firming agent in pickling preparation, as an astringent in medicine, also in drinking water purification, dyeing textiles, tanning leathers and etc.
Ammonium alum vs potassium alum
Both can be used as a major component in deodorant and have advantages over aluminum chloride/chlorohydrate/zirconium, which are usual antiperspirants that function by blocking sweat ducts & glands and may be absorbed by skin.
There are mainly two differences: potassium alum is less acidic and has zero stinging than ammonium alum.
Also, Ammonium aluminium sulfate is a more natural crystal deodorant compared with ammonium alum.
Is Ammonium alum Safe to Eat?
Alums are controversial ingredients as they have been suggested to be associated with Alzheimer’s disease and other neurodegenerative diseases in humans.
Although its safety as a food additive has been approved by the U.S. Food and Drug Administration (FDA), European Food Safety Authority (EFSA), as well as the Joint FAO/WHO Expert Committee on Food Additives (JECFA), its uses in food have limited or even banned in many countries, such as Europe, Japan and China due to the restrictions for aluminum-containing food additives.
FDA
Ammonium aluminium sulfate is generally recognized as safe (GRAS) in food when used in accordance with good manufacturing practice.
EFSA
Aluminum ammonium sulfate (E523) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized in “ Additives other than colours and sweeteners”.
JECFA
Function Class: food additives, buffer, neutralizing agent, colour fixative.
Provisional Tolerable Weekly Intake (PTWI): a PTWI of 2 mg/kg bw was established for aluminium-containing food additives: aluminium ammonium sulphate, sodium aluminium phosphates (acidic and basic), sodium aluminosilicate, calcium aluminium silicate and aluminium silicate in 2011.
Conclusion
Now you may have a knowledge of the alum – Ammonium Alum (E523), from the following aspects:
Manufacturing process
Uses
Compare with potassium alum
Safety
A chemical product in the form of odorless, colorless crystals having a strong astringent taste which is soluble in water and glycerol, is insoluble in alcohol, is derived by crystallization from a mixture of ammonium and aluminum sulfate and is used as a mordant in dyeing, in water and sewage purification, in sizing paper, in retanning leather, as a clarifying agent, as a food additive, in baking powders, in the cereal industries, as a buffer and a neutralizing agent in milling, in the manufacture of lakes, pigments, vegetable glue and artificial gems, for fireproofing, and in the treatment of fur.
OBS
aluminium ammonium bis(sulfate)dodecahydrate: form recommended by the IUPAC (International Union of Pure and Applied Chemistry).
OBS
The IUPAC recommends the form "aluminium" instead of "aluminum."
OBS
Chemical formula: AlH4NO8S2 or Al4(SO4)3(NH4)2SO4.24H2O or AlNH4(SO4)2·12H2O or NH4Al(SO4)2·12H2O or Al2(SO4)3,(NH4)2SO4,24H2O
Aluminium ammonium sulphate is used as a bird and animal repellent.
Ammonium aluminium sulfate is highly soluble in water, non-volatile and non-persistent in soils.
Ammonium aluminium sulfate is moderately toxic to mammals and a recognised irritant.
Ammonium aluminium sulfate is relatively non-toxic to fish and aquatic invertebrates.
Method of manufacturing anhydrous aluminum sulphate
This invention relates to the manufacture of a substantially anhydrous and water soluble aluminum sulphate, the object of my invention being to provide an effective and relatively economical process, for the manufacture of the substantially anhydrous water soluble aluminum sulphate.
Broadly speaking, this invention may be considered as a process using as a starting material a basic ammonium alum, the composition of which is approximately expressed by the following formula: although, practically speaking, this invention will be most usefully applied to the treatment of ores of alumina for the preparation therefrom of normal ammonium alum and the preparation from the normal ammonium alum of the basic ammonium alum and the cyclical use of the ammonium sulphate and sulphuric acid of the normal alum and basic alum, in the treatment of further bodies of ore.
Assuming the use of a basic ammonium alum as a starting material, this invention consists in mixing with the basic alum sulphuric acid in quantity sufficient to combine with the uncombined alumina of the basic alum and, for the best results as affecting the cost of the process, the acid used should have a strength of not less than Baum.
Ammonium aluminium sulfate use of a more dilute acid would involve greater furnace costs as the acid would first be concentrated by the evaporation of the excess water to approximately 50 Baum before a complete reaction would occur.
After thoroughly mixing, the paste formed by the acid and basic ammonium alum, which should be finely divided, is heated, preferably in a mufile furnace, through arrange of temperatures from 200 to 600 C.
also volatilize the ammonium sulphate which must 'berecovered.
Ammonium aluminium sulfate residual product will be found to bean anhydrous water soluble aluminum sulphate.
While this process in its broader scope, can be applied to the described treatment of a basic ammonium alum produced from any raw material, its most nseful application lies in its application to the treatment of aluminum ores as a starting material, with the cyclicaluse of the; mother liquor-produced in the formation of a basicammonium alum precipitate and of the ammonium sulphate separated from thelbasic alum in the described ,
6)step in which the mixture of basic alum and sulphuric acid is heated to form the anhydrous aluminum sulphate and volatilize the ammonium sulphate constituent of the basic alum.
In this embodiment of the invention, the ore of alumina is treated, such ores for example as bauxite, kaolin, or the like, with sulphuric acid to extract its alumina constituent, as a solution of aluminum sulphate and,
with many ores, Ammonium aluminium sulfate is advisable, in order to U obtain a reasonably complete extraction of the alumina,values,'to subject the ores to a preliminary roasting to dehydrate them.
Ammonium aluminium sulfate to the aluminum sulphate solution is added a solution of ammonium sulphate,sullicient to bring the solution to the composition of a solution of a normal ammonium alum.
Ammonium aluminium sulfate ammonium sulphate solution can be added to the aluminum sulphate solution at any stage of its preparation but is preferably added in admixture with the sulphuric acid used in leaching the bores.
The am.- monium alum solution is separated from gangue material and, for the preparation of a pure end product, must ordinarily be treated in any ;well known manner to eliminate soluble impurities, a process which generally involves the crystallization of the alum from the solution, the values in the mother liquor being salvaged by using the mother liquor as a part of the leach in the treatment of further bodies of ore.
Where the normal alum has been crystallized from the solution, it is re dissolved and, for the best results, it has been found that a solution containing 80% of alum is best adapted for the next step of the process which involves the heating of the normal alum solution under pressure to temperatures of 140 to 200 (3., as a result of which a reaction takes place involving the formation and precipitation of the basic ammonium alum and a residual mother liquor containing in solution 55% of the sulphuric acid constituent of the normal alum which has been converted into a basic alum and 67% of the ammonium alum constituent of the basic alum so converted, together with such portion of the normal alum as has not been decomposed.
Ammonium aluminium sulfate basic alum precipitate is then mixed with sulphuric acid and the mixture heated, as already described, to form an anhydrous aluminum sulphate and to eliminate by vaporization the ammonium sulphate of the basic alum, which is then recovered as an aqueous solution, preferably by absorbing the ammonium sulphate in the mother liquor from which the basic ammonium alum is precipitated, although the ammonium sulphate can'be recovered by absorption in water, which is afterward mixed with-the mother liquor.
Ammonium aluminium sulfate mother liquor and the ammonium sulphate solution, with the addition of such sulphuric acid as may be necessary to raise the strength of the acid in the mother liquor to a reactive quantity and with the addition of such ammonium sulphate as may be necessary for the formation of a normal ammonium alum solution, is then used in the leaching of additional bodies of aluminum ore and the formation of the nor mal ammonium alum solution, to be further treated as described.
Ammonium aluminium sulfate will be seen that in the described process using an aluminum ore as a base material, the cyclical use of the sulphuric acid separated from the normal alum in the formation of the basic alum avoids the loss of a considerable quantity of sulphuric acid, while the cyclical use of the ammonium sulphate separated from the normal alum in the formation of the basic alum and separated from the basic alum during the furnace operation to which Ammonium aluminium sulfate is subjected, avoids the loss of these values and makes necessary in the treatment of further bodies of ore only the additional supply of such ammonium sulphate as may be required to make up for losses involved in the manufacturing process.
Losses of ammonium sulphate are also very materially lessened by the elimination from the normal alum of 67% of its ammonium sulphate constituent during Ammonium aluminium sulfate conversion into a basic alum so that only 33% of the ammonium sulphate constituent of the normal alum remains to be eliminated from the basic alum by the described furnacing operation during which the greater part of the losses of ammonium sulphate occur.
Ammonium aluminium sulfate is also to be pointed out that the use of the basic ammonium alum in connection with a reactive quantity of sulphuric acid forms, by reason of the composition and fine division of the basic alum, a mixture which is particularly well adapted for use in the furnacing operation, which effects the reaction between the uncombined alumina and the elimination of the ammonium sulphate constituent of the mixture.
Ammonium aluminium sulfate will be noted that this process is adapted for the production of an anhydrous water soluble sulphate of alumina of any desired degree of acidity or basicity.
This can be controlled by varying the quantity of sulphuric acid mixed with the basic alum and also, where the quantity of acid is, for instance, sufficient to form an acid sulphate, by continuing the heating at the higher tem: peratures for a sufficient time to drive off any desired proportion. of the sulphuric acid radical.
The final product of this process has been referred to as water soluble.
By this is meant an aluminum sulphate which is soluble within the ordinary commercial acceptance of the term.
Generally, there will be a small percentage, say in the neighborhood of .2 of 1% of an insoluble material.
As an example of the carrying out of this 1." process.
Ammonium aluminium sulfate is started with a soft Georgia kaolin of the composition:
Percent Alumina 38 01 Tater 14.27 Silica 44. 65 Potash 0. 17 Calcium oxide 0. 04 Magnesia 0. 13 Ferric oXide 1. 20 Titania 1.44 M Phosphorous pentoxide 0.09
The kaolin is disintegrated and roasted for one hour at 600 C. in a rotary kin, thereby eliminating the water content, increasing the rate of solution of the alumina in the acid and decreasing the iron oxide solubility to 25% of the total present in the ore.
After cooling to 200 (1., he ealcine is treated with an acid solution containing 14% sulphuric acid and 6.3% ammonium sulphate in Pachuca tanks arranged for countercurrent flow.
The reaction is complete in one hour. 90% of the alumina present in the calcine is dissolved as aluminum sulphate.
50% of the calcium oxide, magnesia, and
phosphorous pentoxide will be found in the neutral alum solution, which will be an approximately 55% ammonium alum solution.
A solution of barium sulphide is fed into the last Pachuca tank to reduce the dissolved ferric sulphate to ferrous sulphate, in which case the alum crystallized will be iron-free.
Ammonium aluminium sulfate major portion of the insoluble residue is separated by settling in cones, which also function as washers.
The finely divided insoluble residue which is not settled in the cones, is removed from the liquor by filtration through filter presses, yielding a clear alum solution.
Ammonium aluminium sulfate clear ammonium alum solution, discharged at a temperature of 80 C. from the filter presses, is cooled and crystallized in spray coolers.
The crystals and mother liquor are separated by settling and filtration on a vacuum type filter, Where the crystals are Washed.
About one-third of the mother liquor is cooled from room temperature to 0 C. by refrigeration, the alum crystals removed and the refrigerated liquor discarded.
Ammonium aluminium sulfate remaining mother liquor is returned to the system and used to make up fresh batches of leach solution.
Ammonium aluminium sulfate alum crystals are dissolved by 'con- (lensing steam to make an 80% solution, which is heated to 200 C. in an autoclave. 80% of the alumina will be precipitated as basic ammonium alum with the simultaneous formation of a sulphuric acid-ammonium sulphate solution.
After cooling, the precipitate is separated from the liquor by settling and filtration on a vacuum filter, on which the precipitate is washed.
Ammonium aluminium sulfate mother liquor is returned to the leach system to make up the fresh solvent required.
Ammonium aluminium sulfate precipitate discharged from the filter contains moisture up to 30% of the dry weight.
Ammonium aluminium sulfate moist basic ammonium alum is dried to about 4% moisture content and then mixed with 0.7 parts of 63 Baum sulphuric acid.
This mixture is heated gradually from 200 C. to a final temperature of 600 C.
Ammonium aluminium sulfate reaction between the acid and the basic alum proceeds rapidly at the lower temperatures forming a mixture containing some free acid and about 5% of water-insoluble matter-
Ammonium aluminium sulfate treatment at the higher temperatures for one hour eliminates the ammonium sulphate constituent and reduces the amount of insoluble matter.
After cooling, the mixture will be an anhydrous aluminum sulphate with a very small percentage of insoluble matter, well within the limits of commercial specifications.
Using the above proportions of acid and basic alum the final product will contain a small percentage of soluble basic alumina.
The method of manufacturing a substanti ally anhydrous water soluble aluminum sulphate which consists in mixing with precipitated basic ammonium alum, sulphuric acid in sufiicient quantity to combine with the basic alumina of the basic alum to form soluble aluminum sulphate, heating the mixture to from 200 to 600 0., to cause reaction between the basic alum and the sulphuric acid and the volatilization of water and ammonium sulphate and the production of a substantially anhydrous soluble sulphate of alumina.
2. The process of manufacturing a water soluble substantially anhydrous sulphate of alumina from ores of alumina, which con sists in treating an ore of alumina to extract therefrom its alumina constituent as aluminum sulphate, mixing with the so obtained aluminum sulphate, ammonium sulphate in sufficient quantity to form a solution of a neutral amonium alum, heating the am monium alum solution under pressureto temperatures between 140 and 200 0., to effect the formation and precipitation of a finely divided basic ammonium alum and of a mother liquor consisting of a solution of sulphuric acid and ammonium sulphate, separating the basic ammonium alum from the mother liquor and mixing it with sulphuric acid in sufficient quantity to combine with the basic alumina of the basic alum to form soluble aluminun'i sulphate, heating the mixture to from 200 to 600 C.
To cause reaction between the basic alum and the sulphuric acid, and the volatilization of water and ammonium sulphate and the production of a subtsantially anhydrous water soluble sulphate of itllllnlni-L, recovering ammonium sulphate volatilized and using said ammonium sulphate together with the mother liquor from which the basic alum is precipitated in the formation of normal ammonium alum from fresh bodies of ore.
Description
A white crystalline powder that is also called ammonium alum.
Aluminum ammonium sulfate occurs naturally as the mineral tschermigite.
Ammonium aluminium sulfate is used in baking powders, dyeing textiles, tanning leathers, and as a substrate for lake pigments.
Ammonia alum is also used in developing baths for black and white photographs.
Synonyms and Related Terms
ammonia alum; ammonium aluminum sulfate; alum NF; aluminum ammonium sulphate (Br.); tschermigite
Risks
Skin contact may cause allergies.
Physical and Chemical Properties
Soluble in water, glycerol. Insoluble in ethanol.
Crystals are fibrous and deliquescent
Aluminium Ammonium Sulphate AR, also known as Ammonium Aluminium Sulphate, is supplied as colourless crystals or as a white crystalline powder.
Ammonium aluminium sulfate is freely soluble in water, insoluble in ethanol, and is extremely soluble in hot water.
The key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3, while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4.
What is Aluminum Sulfate?
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3.
This substance is water-soluble and is useful mainly as a coagulant agent during the purification of drinking water and in wastewater treatment plants.
Moreover, this substance is useful in the paper industry.
There are both anhydrous forms and hydrated forms of aluminum sulfate.
Naturally, the anhydrous form can be observed in a rare mineral named millosevichite.
We can find this rare mineral in volcanic sites.
However, the occurrence of the anhydrous form is very rare.
There are different hydrates of aluminum sulfate, which include the hexadecahydrated forms as the most common hydrated form.
Moreover, heptadecahydrate aluminum sulfate occurs naturally in the mineral alunogen.
The molar mass of anhydrous aluminum sulfate is 342.15 g/mo. It appears as a white crystalline solid that is highly hygroscopic.
Sometimes, this substance is known as alum, or as papermaker’s alum according to different applications.
In a laboratory, we can produce aluminum sulfate through the addition of aluminum hydroxide to sulfuric acid or through the heating of aluminum metal in the presence of sulfuric acid.
We can also produce this substance from alum schists which uses a mixture of iron pyrite, aluminum silicate and various bituminous substances.
What is Ammonium aluminium sulfate ?
Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4.
Ammonium aluminium sulfate substance contains an ammonium cation linked to a sulfate anion.
Therefore, it has two ammonium cations per sulphate anion.
We can name this substance as an inorganic salt of sulfate with many important uses.
The molar mass of ammonium sulfate is 132.14 g/mol.
This compound appears as fine, hygroscopic granules or crystals.
Furthermore, the melting point of this compound can range from 235 to 280 °C; above this temperature range, the compound tends to decompose.
We can produce ammonium sulfate compounds by treating ammonia with sulfuric acid.
For this preparation, we can use a mixture of ammonia gas and water vapour in a reactor.
In addition, we need to add concentrated sulfuric acid into this reactor, and then the reaction between these components will form ammonium sulfate.
When considering the applications of ammonium sulfate, we can use it as a fertilizer, mainly for alkaline soils.
Furthermore, we can use it in the production of insecticides, herbicides, fungicides, etc.
In addition to these, we use this compound for the purification of protein via precipitation in the biochemistry laboratory.
Ammonium aluminium sulfate is also useful as a food additive.
Difference Between Aluminum Sulfate and Ammonium Sulfate
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3 while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4.
Ammonium aluminium sulfate key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
The following infographic lists the difference between aluminum sulfate and ammonium sulfate in tabular form.
Summary – Aluminum Sulfate vs Ammonium Sulfate
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3, while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4.
Ammonium aluminium sulfate key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
Used in baking powders and dyes and to make pigment, lakes, artificial gems, vegetable glue, marble and porcelain cements, and paper;
Also used for fireproofing, tanning, copper plating, and as an astringent and styptic;
Used in dyeing (mordant), water and sewage purification (clarifying agent), paper sizing, leather tanning, and fur treatment; (Uses for the dodecahydrate);
Synonyms :
ALUMINUM AMMONIUM SULFATE
7784-25-0
Monoammonium monoaluminum sulfate
Ammonium aluminum sulfate
aluminum;azanium;disulfate
UNII-DPU64XYB1D
DPU64XYB1D
Ammonium alum; Ammonium aluminum alum; Ammonium aluminum sulfate
Caswell No. 041B
Alum, ammonium anhydrous
Aluminum ammonium bis(sulfate)
HSDB 611
Aluminium ammonium bis(sulphate)
EINECS 232-055-3
EPA Pesticide Chemical Code 098501
NSC 146176
Aluminum ammonium disulfate (Al(NH4)(SO4)2)
Aluminum sulfate compd. with ammonium sulfate (1:1)
DTXSID7051428
Aluminium Ammonium Sulphate, Reagent
EC 232-055-3
