Add fluxing agent or active ingredient to the soda-lime jar


Because of its good chemical stability, bottle glass has no pollution to the contents; because of air tightness and high temperature resistance, a certain mechanical strength and reliable use; because of transparent or colorful and help to improve the grade of goods. Therefore, bottle glass is mainly used for product packaging in food, alcohol, beverage, medicine and other industries.

Compressibility, mechanical strength and chemical stability are the main properties of bottle glass. And in the glass compositionSiO2,Al2O3,Its height? R2The content of O is decisive for these properties, and the amount used cannot be changed. How to reduce the energy consumption of glass melting and energy-saving production can only start with promoting the formation stage of silicate, reducing the viscosity and surface tension of glass, and accelerating the clarification and homogenization of glass. General increase some trace flux, active agent raw materials or trace elements.

1.1 addition of trace amounts of Li2O

  Li+It does not belong to the inert gas type ion, the ion radius is small, the electric field strength is large, the asymmetric center is formed in the structure at high temperature, and the oxygen ion can be polarized, which can reduce and destroy the silicon oxygen bond (O/Si. Therefore, Li.2O in glass than K2O its Na2O has a stronger bond breaking effect and is a strong flux. The introduction of about 0.1-0.15% of Li into the glass formulation2O, can reduce the melting temperature of glass, accelerate melting, improve glass production and quality.[1]

   In the alkali-silica glass, the alkali metal mainly promotes melting in the glass. When the total content of alkali metal oxides in the glass is unchanged, and one alkali metal oxide is gradually replaced by another, the nature of the glass is not a linear change, but an obvious extreme value appears, resulting in"The Mixed Alkali Effect". The "mixed alkali effect" brought about by the simultaneous presence of two alkali metal oxides in the glass is more single Na2O has a better fluxing effect.

Bottles and cans of glass because it is a packaging container, the use of popular, large demand, low product cost, in order to meet market demand. The cost of lithium carbonate is relatively high, and lithium-containing minerals are generally selected, such as spodumene, lithium porcelain stone, etc., of which lithium porcelain stone has the lowest relative cost. The mineral contains 1.3-1.8% Li2O, while the introduction of F is a glass accelerator that can accelerate the reaction of glass, reduce the viscosity and surface tension of glass, promote the clarification and homogenization of glass liquid, and increase the thermal permeability of glass. Therefore, lithium porcelain stone as a glass raw material, not only in the glass formula to introduce about 0.1-0.2 Li2O can also introduce about 0.1-0.2% of F, the combined effect of the two can reduce the melting temperature of the glass, to save energy, reduce costs, improve economic efficiency.

chemical composition

SiO2

Al2O3

CaO

R2O

Fe2O3

F

Li2O

Proportion (%)

69-71

17-18.5

1.1-1.4

5-6.5

≤ 0.08

1

1.3-1.8

Table1 The oxidation composition of Jiangxi Yifeng lithium porcelain stone

  simultaneously from the table1 It can be seen that the chemical composition of lithium porcelain stone in addition to containing trace iron Fe2O3In addition, other ingredients are required for ordinary soda-lime bottle glass. especiallyAl2O3content upAbout 17%, can replace some feldspar and aluminum hydroxide raw materials in the formula; 5-6.5% r2O with the introduction, can save the cost of higher soda ash usage. Therefore, lithium porcelain stone is an ideal raw material for ordinary bottles and jars of glass.

1.2 the addition of trace amounts of phosphate rock powder, the introduction of P2O5As an active agent

Adding phosphate rock powder to flat glass has gradually become a common practice. The main composition of phosphate rock is 3Ca3PO42,CaF. During the glass melting reaction, phosphate rock reacts with quartz sand as follows:

     3Ca3PO42SiO2Na2CO3↔2 [na]2O·2CaO·P2O5] 2CaSiO3CO2

 Experiments show that the reaction has been completed below 1250 ℃, which effectively reduces the glass formation temperature and accelerates the formation of glass. At the same time, p2O5In the glass can reduce the high temperature viscosity and surface tension of the glass. WhenP2O5JoinAt 0.04 ° C., the viscosity is reduced by 10 to 30dPa · s at 1422 ° C., and the viscosity is reduced by 60dPa · s at 1322 ° C. Add 0.0133molP2O5InAt 1300 ℃, the surface tension of soda lime glass solution can be reduced by 0.012N/m. Lowering the surface tension contributes to the fining and homogenization of the glass. Experience has shown that 0.35%P is added to the glass2O5Melting capacity can be improvedAbout 4%, energy consumption can be reduced by 4-6%.

1.3 introduction of WO to promote silicate formation3

   WO3Can be mixed withSiO2,Al2O3Such as refractory compounds to form low-temperature eutectics, accelerate the formation of silicate reaction time. SimultaneouslyWO3It is also an active substance, which can reduce the viscosity and surface tension of the glass liquid. ButWO3Is a precious metal, the use of a large number of chemical costs increased, as a bottle of glass raw materials to use unrealistic, you can choose tungsten tailings instead.WO3Economical and cost-effective. in tungsten tailingsWO3Content0.01-0.11%, the rest of the SiO2,Al2O3,Its height? R2O, CaF and the like are all required for the composition of the glass. Fe2O3The content is not high, suitable for use in bottles and cans.

chemical composition

SiO2

Al2O3

CaO

R2O

Fe2O3

WO3

CaF

Proportion (%)

76.2-86.3

7.8-8.4

0.2-1.3

3-5

0.6-1.6

0.01-0.11

0.4-5.3

Table2 Oxidation composition of tungsten tailings in Jiangxi

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