WO2002087796A1 - A process and plant for disposal of products containign asbestos - Google Patents

Abstract

The process comprises the following stages: a first breaking-up of the products; grinding; stocking; inertization in furnace; final storing in containers. At least the first four stages listed above are carried out in an isolation cell (11) kept at a slightly lower pressure with respect to the outside environment.

Description

Description

A Process and Plant for Disposal of Products containing Asbestos

Technical Field

Specifically, though not exclusively, the invention is usefully applied for the disposal of products containing asbestos, such as "Eternit", a cement-asbestos mix, having the form of corrugated covering elements.

Background Art Difficulties in the disposal of these products are well-known.

The present invention resolves the problem by providing a simple process which gives rise to in inert and easily-storable final product.

An advantage of the invention is that it can be actuated using well-known plant units of tried and tested efficiency in various areas of know-how. These aims and more besides are all attained by the invention as it is characterised in the claims that follow.

Disclosure of Invention

Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of some preferred but non- exclusive embodiments of the invention, illustrated purely by way of example in the appended figures of the drawings, in which: figure 1 is a diagram of a first embodiment of the invention; figure 2 is an enlarged-scale detail of figure 1; figure 3 shows, in enlarged-scale, apart of a diagram of a second embodiment of the invention.

The process of the invention in the diagram illustrated in the figures of the drawings comprises the following stages: a first breaking-up of the products; grinding; stocking inertization in furnace; final storing in containers.

At least the first four stages listed above are carried out in an isolation cell 11 kept at a slightly lower pressure with respect to the outside environment.

A characteristic of the plant is that the first breaking-up and the grinding-down are done in a continuous process.

The elements 1 to be treated 1, consisting of products containing asbestos such as "eternit" tiles, are prevalently constituted by corrugated covering elements.

These elements 1 are sent by a feeder 2 to a belt breaker comprising two facing mobile branches of at least two ring-wound belts 3 and 4. The two mobile branches move at the same speed and are supported on support rollers 13 and 14 the presence of which force the elements caught between the two facing branches through a passage which will lead to their breaking-up.

A system of conveyors, indicated in their entirety by 12, collect the broken-up material and drop it in the hopper 15 of a screw 16 which feeds a continuous mill 5.

The screw 16, apart from having the task of continuously feeding the mill 5, also has the task of contributing to a further grinding-down of the material.

The continuous mill 5 of the first embodiment is of a type performing a dry- milling operation. The ground product is transferred on a conveyor 6 to a furnace 7 where it is subjected to an inertization fusion process which gives rise, after cooling, to a solid and inert material. The ground product obtained from the continuous mill 5 is introduced into the furnace, where it is deposited at the top of a system of inclined planes 17, constituting the bottom of the furnace, along which the fusion process occurs; the material then solidifies. In a second embodiment, a part of which is illustrated in figure 3 (corresponding to the part of plant denoted by A in figure 1), a wet-grind is performed in a continuous mill 25 which unloads the ground product, constituted by a fine suspension of solid in water, into a storage bath 19.

The ground product 19 is removed from the bath 19 with the use of a pump 20 and is introduced into the furnace 7 after passing though a device 21 where the water is evaporated away.

The dried material is deposited at the top of a system of inclined planes, constituting the floor of the furnace, along which the material is fused and then solidifies. The solidified material is then put in a collection container 8. The container is normally inside the isolation cell 11 containing the entire plant; the solidified and cooled material can be removed from the cell 11 by bucket elevators 18, and is taken to waiting containers 10.

The material obtained by the process is inert and can easily and unproblematically be stored or used in constructions as aggregate.

Claims

Claims.

1). A process for disposal of products containing asbestos, wherein the process comprises the following stages: a first breaking-up of products; grinding; stocking inertization in furnace; final storing in containers; at least the first four of the stages being carried out in an isolation cell (11). 2). The process of claim 1, wherein the isolation cell (11) is kept at a lower pressure than a pressure of the outside environment.

3). The process of claim 1 or 2, wherein the first breaking-up of the products and the grinding of the products are done continuously.

4). A plant for actuating the process of claim 3, wherein the first breaking-up of products is realised by use of belt breakers comprising at least two facing mobile branches of at least two ring-sound belts (3 and 4).

5). The plant of any one of the preceding claims, wherein the grinding is done by use of a continuous mill (5).

6). The plant of claim 5, wherein the fusion for inertization is realised in a tank furnace in which the product when ground is introduced and deposited at a top of a system of inclined planes along which the material is fused.