A kind of commercial fluorided aluminium is except sodium technique
Technical field
The present invention relates to a kind of commercial fluorided aluminium except sodium method, object reduces sodium content in industrial aluminum fluoride.
Background technology
The production of current industrial aluminum fluoride has the scheme of a variety of maturation, such as: wet process technique, dry technology for production, thick sour dry technology for production etc.React obtained aluminum fluoride by the hydrogen fluoride gas after refining and aluminum hydroxide slime, because material purity is all very high, obtained aluminum fluoride purity is also very high, so do not have the puzzlement of sodium ion.But when adopting other technique to produce aluminum fluoride, because by raw material and process technology limit, more or less all can introduce sodium ion, this will cause in the aluminum fluoride obtained containing a small amount of sodium ion.Sodium impurity content more (Na >=2.8) in aluminium fluoride product, purity and the grade of aluminum fluoride will be reduced, affect electrolytical molecular ratio and specific conductivity, and then affect the technology stability of electrolytic aluminum, reduce the use properties of aluminum fluoride, add the aluminum fluoride consumption of ton aluminium and the discharge of pollutent simultaneously.Based on this, in order to improve the quality of aluminum fluoride, be necessary to remove the sodium impurity in aluminium fluoride product.Because the current research to this respect is few, therefore, also there is no mature technology technique and the method that effectively can reduce sodium content in aluminum fluoride at present.
Summary of the invention
The present invention is directed to prior art deficiency, propose a kind of commercial fluorided aluminium except sodium technique, by this processing method, effectively can reduce the content of impurity natrium in aluminum fluoride, improve the purity of aluminum fluoride.
Aluminum fluoride crystal structure has the multiple crystal formation such as α, β, γ, ε, δ, η, θ, κ, there is solvable metasable state α-AlF
33H
2β-the AlF of O and indissoluble
33H
2o, and β type AlF
33H
2o is the most stable within the scope of 0 ~ 100 DEG C.Aluminium and hydrofluoric acid aqueous solution can obtain α type AlF lower than 25 DEG C of reactions
33H
2o, under dampness, α type can be transformed into β type AlF slowly
33H
2o, or be heated and directly irreversiblely become β type.The β type AlF of indissoluble
33H
2o can obtain Anhydrous Aluminium Chloride product through 400 DEG C of calcinings.Principle is as follows:
2Al + 6HF → 2α-AlF
3·3H
2O + H
2
α-AlF
3·3H
2O →β-AlF
3·3H
2O
β-AlF
3·3H
2O → AlF
3
Commercial fluorided aluminium mainly exists with the form of β type Trihydrate, under lower drying temperature, first loses bimolecular crystal water; Most of surplus crystal water is lost under comparatively high dry temperature.Reaction equation is as follows:
AlF
3·3H
2O → AlF
3·H
2O + 2H
2O
AlF
3·H
2O → AlF
3·0.5H
2O + 0.5H
2O
AlF
3·0.5H
2O → AlF
3+ 0.5H
2O
AlF
3be heated to 300-400 DEG C of energy and be decomposed into hydrogen fluoride and aluminum oxide by water vapor portion, temperature is more than 500 DEG C, and hydrolysis reaction is violent, and reaction equation is as follows:
2AlF
3+ 3H
2O → Al
2O
3+ 6HF
The aluminum fluoride of β type is slightly soluble in water, acid and alkaline solution, even be heated to be fuming with the vitriol oil still Fails To Respond, and the sodium element in the crude product aluminum fluoride of industry preparation mainly exists with the form of sodium fluoroaluminate, and sodium fluoroaluminate can decompose in concentrated sulfuric acid completely, in view of above difference, we react with the vitriol oil and sodium fluoroaluminate, generate sodium sulfate and hydrofluoric acid, then wash to remove sodium.Reaction equation is as follows:
2Na
3AlF
6+ 6H
2SO
4→ 3Na
2SO
4+ 12HF↑ + Al
2(SO
4)
3
Based on this, present invention employs following technical scheme:
A kind of commercial fluorided aluminium is except sodium technique, and its step comprises:
1) first by the roasting at 200 ~ 400 DEG C of commercial fluorided aluminium, make it to be converted into β type by α type;
2) then add the vitriol oil according to the solid-to-liquid ratio of 1:10 ~ 20, stir at normal temperatures, mix, make it abundant reaction, make sodium fluoroaluminate wherein be converted into solvable sodium sulfate and Tai-Ace S 150;
3) then thin up, amount of water is 2 ~ 3 times of the vitriol oil volume used, and filters and obtains filter cake;
4) filter cake is washed with water;
5) to filtration cakes torrefaction, obtained pure aluminum fluoride.
Described commercial fluorided aluminium is except sodium technique, and before the commercial fluorided aluminium of roasting makes it transition, adopt the mode roasting that staged heats up to make it dry, the aluminum fluoride first industry prepared is dry 2 ~ 3h at 100 ~ 120 DEG C, removing product surface water; And then at 150 ~ 200 DEG C of temperature dry 2 ~ 3h, removing Bound moisture.
Described commercial fluorided aluminium, except sodium technique, adopts the method exclusion of water steam vacuumized, to prevent the hydrolysis of aluminum fluoride in roasting transformation process.
Described commercial fluorided aluminium is except sodium technique, and in step 1), the commercial fluorided aluminium of roasting makes it to be converted into β type completely by α type, and maturing temperature controls at 250 ~ 350 DEG C, and roasting time controls between 1 ~ 2h.
Described commercial fluorided aluminium removes sodium technique, step 2) in, the vitriol oil concentration of employing, more than 98%, adds the vitriol oil according to solid-to-liquid ratio 1:10 ~ 12.
The useful positively effect of invention:
1, the commercial fluorided aluminium of the present invention is except sodium technique, solves and utilizes potassium felspar sand to prepare the problem that in aluminum fluoride production technique, in aluminum fluoride, sodium impurity content is high, achieve the comprehensive utilization of potassium felspar sand.Except potassium element, also containing aluminium element in potassium felspar sand, in order to realize the comprehensive utilization of potassium felspar sand, just needing to manage aluminium element also to extract.Consider that if utilize aluminium element to prepare aluminum fluoride, not only added value is high, but also make use of this part of fluorine, decreases the waste of fluorine resource natively containing fluorine in potassium felspar sand leaching liquid.
2, the commercial fluorided aluminium of the present invention is except sodium technique, effectively can reduce the content of sodium in aluminum fluoride, improves quality and the result of use of aluminum fluoride, makes the content of sodium in aluminum fluoride reach national standard reference (Na≤2.8).By the process of this processing method, in make to utilize potassium felspar sand to be prepared aluminum fluoride that aluminum fluoride production technique obtains, the content of sodium is less than 2.8%, reach the requirement of technical grade aluminum fluoride, the rate of recovery of aluminium element reaches 85% simultaneously, achieve the comprehensive utilization of potassium felspar sand, be conducive to comprehensive utilization and the saving of resource, good Social benefit and economic benefit can be produced.
3, the commercial fluorided aluminium of the present invention is except sodium technique, adopts the mode roasting that staged heats up, and first removes surface water at a lower temperature, then removes Bound moisture at relatively high temperatures, and vacuumize, exclusion of water steam, to prevent the hydrolysis of aluminum fluoride.
Accompanying drawing explanation
Fig. 1 is that the commercial fluorided aluminium of the present invention is except sodium process flow diagram.
Embodiment
Below by embodiment, technical scheme of the present invention is described in further detail.
embodiment 1
See Fig. 1, the commercial fluorided aluminium of the present invention is except sodium technique, and implementation step is:
1) first by the roasting at 200 ~ 400 DEG C of commercial fluorided aluminium, make it to be converted into β type by α type;
2) then add the vitriol oil according to the solid-to-liquid ratio of 1:10 ~ 20, stir at normal temperatures, mix, make it abundant reaction, make sodium fluoroaluminate wherein be converted into solvable sodium sulfate and Tai-Ace S 150;
3) then thin up, amount of water is 2 ~ 3 times of the vitriol oil volume used, and filters and obtains filter cake;
4) filter cake is washed with water;
5) to filtration cakes torrefaction, obtained pure aluminum fluoride.
embodiment 2
The difference of the present embodiment and embodiment 1 is, adopts preferred mode, and in step 1), the commercial fluorided aluminium of roasting makes it to be converted into β type completely by α type, and maturing temperature controls at 250 ~ 350 DEG C, and roasting time controls between 1 ~ 2h.
embodiment 3
The commercial fluorided aluminium of the present embodiment is except sodium technique, and the difference of itself and embodiment 1 or embodiment 2 is: adopt preferred mode, step 2) in, the vitriol oil concentration of employing, more than 98%, adds the vitriol oil according to solid-to-liquid ratio 1:10 ~ 12.
embodiment 4,5,6
The commercial fluorided aluminium of these three embodiments, except sodium technique, is with the difference of foregoing embodiments: respectively at the method exclusion of water steam adopting in roasting process and vacuumize that makes the transition, to prevent the hydrolysis of aluminum fluoride.
embodiment 7,8,9
The commercial fluorided aluminium of these three embodiments is except sodium technique, be with the difference of embodiment 1,2 and 3 respectively: before the roasting that makes the transition, first carry out drying and roasting to commercial fluorided aluminium to dewater, adopt the mode roasting that staged heats up, first aluminum fluoride industry prepared is dry 2 ~ 3h at 100 ~ 120 DEG C, removing product surface water; And then at 150 ~ 200 DEG C of temperature dry 2 ~ 3h, removing Bound moisture, and then carry out roasting process transition.
Further, making the transition in roasting process, by adopting the method exclusion of water steam vacuumized, to reach the object of the hydrolysis preventing aluminum fluoride.
The commercial fluorided aluminium of the present invention is except sodium technique, and technical scheme is scientific and reasonable, can reach desirable except sodium effect.In the present invention is except the commercial fluorided aluminium of sodium art breading, the content of sodium can reach national standard reference, has good feasibility, is conducive to the comprehensive utilization realizing potassium felspar sand, economizes on resources.
Here be carry out in laboratory to except the experiment of sodium analysis of Influential Factors, the feasibility demonstrating technical solution of the present invention and the effect that can reach.
1. sulfuric acid concentration is on the impact except sodium result
The aluminum fluoride crude product first industry prepared is at 110 DEG C of dry 2h, roasting at 400 DEG C, then gets about 10g sample respectively, and one group adds 100ml water, one group of sulphuric acid soln adding 100ml volume ratio 1:1, one group adds the 100ml vitriol oil, at 30 DEG C of stirring reaction 2h, then adds 300ml water dilute filtration, use 60 DEG C of hot wash filter cakes again, cooling, again at 600 DEG C of roasting 2h after drying, fluorometric result is as follows:
Table 1: different concns sulfuric acid is on the impact of sodium content in aluminum fluoride
Title/composition |
Washing aluminum fluoride is except sodium |
1:1 sulfuric acid is except sodium |
The vitriol oil is except sodium |
F |
50.05 |
52.38 |
54.13 |
Na |
3.33 |
2.81 |
0.27 |
Al |
35.95 |
38.33 |
41.60 |
K |
0.86 |
0.79 |
0.81 |
Ca |
5.66 |
1.91 |
1.52 |
Fe |
0.75 |
0.76 |
0.76 |
From detected result, the vitriol oil is used to remove sodium effect better.
2. aluminum fluoride temperature transition is on the impact except sodium result
Get industrial crude product respectively and be about 10g aluminum fluoride crude product, at 400,300,200 DEG C of roasting 2h, then add the 100ml vitriol oil 30 DEG C of stirring reaction 2h, add 300ml water dilute filtration, then use 60 DEG C of hot wash filter cakes, dry, fluorometric result is as follows:
Table 2: the different temperature that makes the transition is on the impact of sodium content in aluminum fluoride
Title/composition |
400℃ |
300℃ |
200℃ |
F |
64.67 |
45.93 |
52.89 |
Na |
1.65 |
0.48 |
1.14 |
Al |
29.64 |
32.71 |
39.49 |
K |
0.72 |
0.91 |
0.87 |
Ca |
1.37 |
1.30 |
1.55 |
Fe |
0.38 |
0.57 |
0.76 |
From detected result, roasting aluminum fluoride make it transition preferred temperature be about 300 DEG C, be suitable.
3. temperature of reaction is on the impact except sodium result
Get about 10g aluminum fluoride crude product respectively, 400 DEG C of roasting 2h, add the 100ml vitriol oil, respectively at 30 DEG C, 50 DEG C stirring reaction 2h, then add 300ml water dilute filtration, then use 60 DEG C of hot wash filter cakes, and dry, fluorometric result is as follows:
Table 3: different de-sodium temperature is on the impact of sodium content in aluminum fluoride
Title/composition |
30℃ |
50℃ |
F |
58.75 |
58.84 |
Na |
2.63 |
2.46 |
Al |
33.84 |
34.05 |
K |
0.79 |
0.77 |
Ca |
1.72 |
1.64 |
Fe |
0.57 |
0.60 |
As can be seen from analytical results, temperature of reaction is defined as about 30 DEG C.Temperature is high again, and effect difference is not clearly, and heating needs to consume a large amount of heat, loses more than gain.
Different de-sodium temperature is on the experiment of sodium content impact in aluminum fluoride, 30 DEG C, 40 DEG C, 50 DEG C, 60 DEG C were all done in laboratory, result shows 30 DEG C, 40 DEG C, and change is little, 50 DEG C, 60 DEG C changes are little, so only list 30 DEG C, 50 DEG C two kinds of situations in the table.