WO2005095295A1 - Use of by- pass dust of cement industry in glass manufacture - Google Patents

Abstract

The By-pass dust of Portland cement industry (ordinary or white cement) could be used in the glass manufacture as an alternative raw material instead of sand, partially or completely. The range of its percentage in the glass mixture lays between 10-70% of the total components. The other components are broken glass, the carbonates of each of the following: sodium, potassium, magnesium, barium, arsenic, and aluminum oxide and soda ash and coloring oxides such as the oxides of iron, cobalt and selenium. Blast furnace slag could be added on the account of the by-pass dust to obtain different colors.

Description

USE OF BY- PASS DUST OF CEMENT INDUSTRY IN GLASS MANUFACTURE

TECHNICAL FIELD

Glass industry.

BACKGROUND ART

Glass manufactured from sand at high temperature about 1500°C with some additives as: sodium carbonate, potassium carbonate, barium carbonate, calcium carbonate and arsenic carbonate in addition to some old or broken glass and aluminum oxide, soda ash and coloring oxide such as: cadmium oxide, iron oxide and selenium oxide.

DISCLOSURE OF INVENTION

The use of most of the previous additives could be avoided partially or completely to save money which is an economic purpose. This could be achieved using the by-pass dust of Portland cement industry (ordinary or white) and the blast furnace slag of steel industry. These two materials are by-products and cost nothing. On the other hand, the by-pass dust causes pollution of air.

The composition of the glass production mixture is as follows:

(10-70) wt% by-pass dust or blast furnace slag or a mixture of both of them, depending on the sought after color. The rest of the mixture will be: sand, broken glass, soda ash, aluminum oxide and the carbonate of each or some of the following: sodium, potassium, magnesium, barium and arsenic which are used as glass modifiers. There is no need to add calcium carbonate because the by-pass dust contains 50 wt% calcium oxide.

Note: by-pass dust of white Portland cement is used when non colored glass is needed; while by-pass dust of ordinary Portland cement is used when greenish glass is needed. Blast furnace slag is used when yellowish brown is needed. BEST MODE FOR CARRYING OUT THE INVENTION

This method is valid to be used in all glass factories using sand in silicate glass manufacture. The produced glass is a silicate glass and could be formed in different forms including the plates form.

Claims

1. Method of using the by-pass dust of Portland cement industry (ordinary or white cement) to replace sand partially or completely in silicate glass by the range from 10-70 wt% in addition to the other additive materials which act as glass modifiers.

2. The other additive materials are: The carbonate of each of the following: sodium, potassium, magnesium, barium and arsenic in addition to broken glasses and coloring oxides such as cobalt, cadmium and/or selenium oxides, soda ash and aluminum oxide are also used as glass modifiers.

3. The composition of the glass mixture is: 10-70 wt % by pass dust + 30 wt % of all, or some of, the additives mentioned in the item 2 + broken glass and sand which replace some of the by-pass dust by about 10-30 wt%.

4. The addition of blast furnace slag, which is a by-pass product in steal industry, to the glass mixture on the account of the by-pass dust of cement as mentioned in item 3.

5. The temperature of the glass furnace is 1400 - 1550°C.

6. Different colors of the produced glass could be obtained by adding different transition metal oxides to the glass mixture, such as iron, cadmium, selenium and/or cobalt oxides as well as different non- metals such as carbon and/or sulfur.