The main use of aluminum hydroxide

Aluminum hydroxide is the maximum dosage and the most widely used inorganic flame retardant additive. Aluminum hydroxide can not only be flame retardant, but also prevent smoking, no drops, and no toxic gases. Therefore, it has obtained a widespread application, and the amount of usage is also increasing year by year. Scope of use: thermosetry plastic, thermoplastic plastic, synthetic rubber, coatings and building materials industries. At the same time, aluminum hydroxide is also the basic raw material for aluminum fluoride in the electrolytic aluminum industry, and aluminum hydroxide in the industry is also widely used.
Reagent analysis
Method name:
The measurement of aluminum hydroxide gel -aluminum hydroxide — neutral titration method
application range:
The content of aluminum hydroxide in aluminum hydrolytic gel. This method is suitable for alumina gel.
Method principle:
The test product plus hydrochloric acid and water heating to dissolve, cool, filter, take the continuous filtrate and add ammonia test solution to the precipitation After dissolving, add acetic acid-ammonium acetate buffer (pH6.0), and then precisely add a tetramia tetrabalty sodium diite drip, and boil for 3-5 minutes, cool it, add dysphenol orange indicator liquid, use zinc indicator solution, use zinc, use zinc Dripping the titular drip until the solution is changed from yellow to red. Read the amount of zinc droplet solution and calculate the content of aluminum hydroxide. Reagents:
water (new boiling to room temperature)
⒉ tethamine tethamine tetrazhane sodium drip (0.05 mol/L)
⒊ zinc drip fixed solution (0.05 mol/L)
⒋ Sodium hydroxide test solution
sodium sodium sodium sodium
⒍ benchmark zinc oxide
⒎ thin hydrochloric acid
⒏ chromium black T indicator
⒐ methacopolic orange indicator n⒑ ammonia ammonia ammonia ammonia Test solution
酸 acetic acid-ammonium acetate buffer (PH6.0) Instrument and equipment:
The sample preparation:
⒈ 乙 乙 试 试 试 试 sodium sodium tienate (0.05 mol/L) r
Formula: Take 19g of sodium di -sodium acetate, add new boiling cold water to 1000ml, shake well.
Buid: 0.12g of the benchmark zinc oxide from 800 ° C to a constant weight, precision definition, add dilute hydrochloric acid 3ml to dissolve, add water 25ml, add 0.025%methyl red ethanol solution with 1 drop, drop plus plus plus plus plus plus plus plus plus The ammonia test solution is slightly yellow, and the water is 25ml of water and ammonia-ammonium-ammonium chloride buffer (pH10.0) 10ml. Correct the titration results with blank test. Each 1ml tethamine tetrazhaide di -sodium drip (0.05 mol/L) is equivalent to 4.069mg zinc oxide. According to the consumption of this solution and the amount of zinc oxide, the concentration of the liquid is calculated.
Sta storage: Set the glass plug to avoid contact with rubber plugs and rubber tubes. 0 Zinc Driver (0.05mol/L)
Prefatient: 15g of zinc sulfate (equivalent to about 3.3g of zinc) plus dilute hydrochloric acid 10ml and water to dissolve to 1000ml, shake well.
Blings: 25ml of accurate amounts, 1 drop of ethanol solution with 0.025%methyl red, dripper test solution to the slight yellow color of the solution, 25ml of water, ammonium-ammonium chloride buffer (PH10.0.0 ) A small amount of chromium black T indicator, titer with tetramia tetrazhanal sodium diper (0.05 mol/L) to the solution from purple to pure blue, and tested the results of the titer with a blank test. Based on the consumption of tetramnium tetrazhanal sodium di -sodium drip solution, the concentration of the liquid is calculated, which is obtained.
氧 Sodium hydroxide test solution
The sodium hydroxide 4.3g, add water to solve 100ml, which is obtained. This product should be used for a new system.
盐
The 234ml of hydrochloric acid and diluted water to 1000ml, which is obtained. This liquid contains 9.5-10.5%.
黑 chromium black T indicator
The chromium black T 0.1g, add 10g of chloride na, grind evenly, that is.
甲
In 0.2g of dharma phenol orange, add 100ml of water to dissolve, that is, obtain.
试 ammonia test solution
The dense ammonia solution is 400ml, add water to 1000ml, that is.
-酸 acetic acid-ammonium acetate buffer (pH6.0)
100g of ammonium acetate, add 300ml of water to solve
Operation steps: take about 8g of this product, precisely defined, add hydrochloric acid and water each 10ml heating can dissolve, cool, filter, and place the filter 250ml of 250ml measuring bottle. The filter is washed and incorporated into the bottle with water, diluted with water to the scale, and shakes well. Settlement, add dilute hydrochloric acid until the precipitation is exactly exactly, add 10 ml of acetic acid-ammonium acetate buffer (pH6.0), and then precisely add tethamine tetrabalty tetrabalty dyscitic sodium drop fixed solution (0.05 mol/L) 25ml, and boil boiled In 3-5 minutes, put the cold, add 1ml of phenolic orange indicator solution, titer with zinc drip fixed solution (0.05 mol/L) to the solution from yellow to red, and tested the results of the titer with blank test correction. Each 1ml tethamine tetrazhaide di -sodium drip (0.05 mol/L) is equivalent to 2.549mg AL2O3.
Note 1: “Precision” means that the weight should be accurate to one thousandth of the one thousandth of the weighing weight. The accuracy requirements of the pipe tube.
The baking process
The design of hydroxide baking design (Design of Hydrate for Alumina Refinery)
The craft design of aluminum. The main content of the design is: process process, equipment selection, equipment configuration and main technical indicators.
The processing process
The hydroxide roasting is generally carried out in a rotary kiln or a darning furnace.
. When baking the kiln with a rotary kiln, the washed wet hydrogen aluminum aluminum was fed into one end of the kiln, and the heavy oil or gas was sprayed from the other end of the kiln. The reaction process such as transformation is produced, and alumina is obtained after cooling.
: When baking with a darkened furnace, the wet hydrogen aluminum is first fed into the dryer, and then sent to a darkened roasting furnace, sprayed into the fuel roasting into alumina, and then the stop slot, the multi -stage blasting the heat exchange device The cooling bed cooler cools, which is the final product. The baking system of a darning furnace can make full use of the heat and the heat from the cooling exhaust gas and the material to preheat the gas and air required for the burning. High heat efficiency and low heat consumption are only 60%to 70%of the rotary kiln device.
The combustion exhaust gas of the two processes, both purified the dust collector and rowed into the atmosphere.
The processing process of the darning roasting furnace system is shown in the figure.
The content of the revision of Chinese Pharmacopoeia
2010 version of the Chinese Pharmacopoeia revision and adding content:
aluminum hydroxide
ü
üluminium hydroxide
Book page number: 2005 Edition 2 -405
[Amendment]
The English name is changed from “Aluminium Hydroxide” to “Dried Aluminium Hydroxide”, deleting molecular formula and molecular weight.
“The aluminum containing aluminum aluminum is calculated according to Al2O3, and it must not be less than 48.0%.” The change to “this product aluminum alumina Al (OH) 3 must not be less than 76.5%.”
[Check] “Pharoma (0.1mol/L) per 1g of acid is not less than 230ml per 1g.” Instead of consumed the drop of hydrochloride (0.1 mol/L) per 1g, it must not be less than 250ml. “
This product is 0.10g, adds dilute hydrochloric acid by 3ml, is boiled and dissolved, puts it in Ling, adds water to 50ml, filter; takes 25ml of continuous filtrate, check according to law (Appendix ⅷ B), and the control solution made with the standard potassium sulfate solution 5.0ml of 5.0ml Comparison, we must not be stronger (1.0%).
[Measurement of the content] Take about 0.6g of this product, precisely defined, add 10ml of hydrochloric acid and water, boil and dissolve, add cold to room temperature, transfer to a 250ml measuring bottle, dilute to the scale with water, and shake; The precision amount is 25ml, the ammonia test solution is medium and the precipitation is used to accumulate. Sodium drip fixed solution (0.05mol/L) 25ml, boil for 3 to 5 minutes, cool to room temperature, add 1ml of dysphenol orange indicator solution, titer with zinc drip fixed liquid (0.05 mol/L), until the solution is changed from yellow to red to red , And tested the results of the titer with a blank test. Each 1ml tethamine tetrazhaide di -sodium drip (0.05 mol/L) is equivalent to 3.900mg AL (OH) 3.
[Added]
[Check] Two copies of cadmium to take this product 0.50g, one portion of 4ml of nitric acid, boil and dissolve, put it in the lingering, transfer the 50ml measuring bottle, dilute it with water to the scale, shake well well , Filter, take the filter fluid as test solution (B). Another cadmium standard solution (1.0 μg/ml) is determined separately at the wavelength of 228.8nm, which shall meet the regulations (0.0002%).
Scades to take two copies of this product 1.0g, place a 50ml measuring bottle, and shake it with 4ml of hydrochloric acid in one copy, and shake it with water 25ml. Add 5%hydrochloride solution to purple to disappear, dilute to the scale with water, mix well, filter, take the continuous filtrate as a test product solution (B); In the same method operation, the sequel filter fluid is used as a control solution (A). According to the atom absorbing the lighting method (appendix ⅳ D), it is determined separately at the wavelength of 253.6nm, and the regulations should be compliant (0.0002%).
The medical treatment
The aluminum hydroxide is often used to treat excessive gastric acid. The main component of gastric acid is hydrochloric acid. The use of aluminum hydroxide and gastric acid reactions to generate non -toxic and harmless aluminum chloride to discharge from the body. The reaction equation is: al (OH) 3 3HCL == AlCl3 3H2O
Why use aluminum hydroxide and excessive gastric acid, instead of sodium hydroxide and calcium hydroxide Strong, but it is harmful to the human body and has strong corrosiveness, so it cannot be used to neutralize gastric acid.