PL189202B1 - Wasteless method of utilising a spent vanadium catalyst along with neutralising metal oxides contained therein - Google Patents

Abstract

The method of glass production with waste components included in the process - unique characteristics: A waste product, in the form of used-up vanadium catalysts, is introduced into a known glass-making mixture for producing sodium-calcium glass for domestic and packaging glassware, based on the simple triple-component mixture SiO2-Na2O-CaO. The catalysts are ground to obtain particle size of 0.1-2 mm. The waste product contains the following oxides: 4 - 6 percent of V2O5, 6 - 10 percent of K2O, 0.6 - 1.0 percent of Na2O, 15 - 27 percent of SO4, 40 - 60 percent of SiO2, 0.7 - 1.2 percent of CaO, 1.2 - 1.7 percent of Fe2O, 1.5 - 2.0 percent of Al2O, in the amount of 1-3 percent by mass of the glass-making mixture. The homogenised mixture is melted in a tank furnace.

Description

The present invention relates to a method of producing glass using waste vanadium catalyst waste.

Vanadium catalyst is used in the production of sulfuric acid by the contact method in the oxidation of SO2 to SO3.

The catalyst is vanadium pentoxide on a support which is diatomaceous earth. The catalyst also contains an activator which is usually potassium oxide or sodium oxide. The content of vanadium pentoxide is 5-7% by weight, the content of activator is approximately 35%, and the content of silicate carrier is approximately 60%.

During operation, the catalyst is subject to chemical and mechanical wear. In chemical terms, the vanadium mass is enriched with sulphates, mainly iron and calcium. In addition, the vanadium oxide turns into inactive vanadyl sulfate. The absorption of cyanides, water vapor and others also reduces the catalyst activity.

The decrease in the efficiency of the SO2 oxidation process and the increase in gas flow resistance through the contact tower make it necessary to replace the catalyst.

Due to the content of vanadium compounds, the used catalyst is classified as hazardous waste. This waste should be stored in isolation from the environment, without the possibility of polluting the air, water or soil, and without the possibility of influencing living organisms. Until now, the majority of this waste is stored in tub storages in company landfills, in barrels or plastic bags.

The Polish patent specification No. 177606 describes a method of recovering vanadium from the spent vanadium catalyst, which consists in extracting vanadium compounds with the use of sodium hydroxide with the addition of hydrogen peroxide, and then, by subsequent chemical operations, the vanadium pentoxide is obtained.

Due to the high cost of the chemical process, the formation of troublesome wastewater and the lack of interest in industry, vanadium is not recovered from spent catalysts.

Research is also conducted on the neutralization of waste catalysts in the production of ceramic bricks and in the solidification process in the production of concrete and concrete products. However, due to the amphotericity of vanadium, which can leach out in an alkaline environment, this direction is practically not used in industry. The essence of the invention is the development of a method for the production of glass using waste, in which, according to the invention, waste in the form of spent ground vanadium catalysts is introduced into the known soda-lime glass set for the production of household and packaging glass, derived from the simple three-component SiO2-Na20-Ca0 system for graining 0.1-2 mm with the oxide composition: V20 5 4 - 6%, K20 6 - 10%, Na20 0.6 - 1.0%, S04 15 - 27%, SiO 2 40 - 60%, CaO 0 7 - 1.2%,

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Fe2O 1.2-1.7% Al2O, 1.5-2.0%, in an amount of 1-3% by weight of the glass batch, after which the homogenized batch is melted in the glass bath.

The spent vanadium catalyst is a source of ions which color the glass mass.

The process according to the invention does not deteriorate the quality of the product and guarantees permanent neutralization of all metal oxides, especially toxic vanadium compounds by converting the vanadium compounds into insoluble silicate compounds.

The process according to the invention also uses a catalyst carrier mass as a secondary raw material - a substitute for reactive silica and sodium and potassium compounds.

The use of the used mass from vanadium catalysts as a secondary raw material and a substitute for green dye in the production of container and household glass allows for the binding of metal oxides from vanadium catalysts in the structure of a glassy phase, insoluble in water. This application reduces the consumption of natural, fossil resources, which in turn also leads to the reduction of environmental degradation. Using the method according to the invention, it is possible to obtain a full-value, ecologically safe product, and the technology used is a waste-free technology.

The object according to the invention is presented in more detail in the following embodiment

Example

A basic soda-lime glass set for the production of household and packaging glass was prepared, derived from the simple three-component SiO 2-Na20-Ca0 system.

The oxide composition of the container glass is:

S1O2 - 70.3% Al2O3 - 2.1% Fe2O3 - 0.3%

MgO - 0.5% CaO 3 14.2% Na2O - 12.6%

The oxide composition of household glass is:

S1O2- 76% A1 ₂ O 3-0.8% Fe20 3 - 0.05% MgO-0.1%

BaO - 0.65% CaO 3 7.2% Na ₂ O-13.5% K, O - 1.3%

Used vanadium catalysts, the average chemical composition of which is:

V2O ₅ 4-6%

K, 0 6-10%

Na, 0 0.6-1.0%

SO4 15-27%

S1O2 40-60%

CaO 0.7-1.2%

Fe2O 3 1.2-1.7%

Al20 3 1.5-2.0)% glow loss at 500 ° C 5-10%

The chemical composition of the used vanadium catalyst is similar to the chemical composition of the raw material set for the production of soda-lime glass, basic for the production of domestic and packaging glass, and contains the most important components of the glass mass - silica, alkali, sulphates and lime, and vanadium compounds are additionally coloring compounds .

For example, for 100 kg of glass mass, a set consisting of 68.05 kg of glass sand, 6.98 kg of feldspar, 1.18 kg of limestone, 18.10 kg of dolomite and 27.12 kg of soda was prepared.

By treating the material derived from spent vanadium catalysts as a raw material, it was calculated that its content in the glass pulp should be 1 to 3% by weight of the glass pulp.

To the known glass sets, 1-3% of the dry vanadium mass was introduced from the spent vanadium catalysts, ground to the grain size of 0.1-2 mm. Waste is a brittle material, therefore a roller or cone crusher with an adjustable gap can be used for its grinding. These devices allow coarse grains to be crushed without the formation of a dusty fraction, unfavorable for the glass melting process.

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All components of the glass batch were homogenized in the blender and then melted in the glass furnace.

The addition of ground spent vanadium catalyst allows the replacement of chromium and iron compounds as dyes, and also reduces the amount of the basic raw material sand, which is the main source of silica.

Vanadium ions, depending on the degree of oxidation, color the glass from light green to olive green. The solubility of the vanadium compounds in the glass is quite good and melting is not difficult.

The presence of compounds such as potassium sulfate and calcium sulfate in the spent catalyst is advantageous and allows the reduction of the traditionally used clarifiers and oxidants.

Publishing Department of the UP RP. Circulation of 50 copies

Price PLN 2.00.

Claims (1)

Patent claim A method of producing glass with the use of waste, characterized in that the known soda-lime glass set for the production of household and packaging glass, derived from the simple three-component SiO 2-Na ₂ 0-Ca0 system, is introduced with waste in the form of spent ground vanadium catalysts for graining 0.1-2 mm, with the oxide composition: V 20 5 4 - 6%, K ₂ 0 6 - 10%, Na ₂ 0 0.6 - 1.0%, S04 15 - 27%, SiO 2 40 - 60%, CaO 0.7 - 1.2%, Fe20 1.2 - 1.7% Aty0, 1.5 - 2.0%, in the amount of 1-3% by weight of the glazing batch, then the homogenized batch is melted in the glass bath.