WO1987003296A1

WO1987003296A1 - The production of hard compact carbonaceous material through acid/alkali treatment

Info

Publication number: WO1987003296A1
Application number: PCT/AU1986/000154
Authority: WO
Inventors: Colin Graham Mcallan; John Arthur Harris
Original assignee: Gippsland Institute Of Advanced Education
Priority date: 1985-11-29
Filing date: 1986-05-29
Publication date: 1987-06-04
Also published as: EP0246242A1; AU5088885A

Abstract

Carbonaceous material, including wood based material, coal, lignite, peat and like carbonaceous material, is ground to a fine state, either with or without previous drying procedures, added to water and aqueous alkali to form a paste, exhibiting gel like properties and extruded to form pellets or applied as a slurry to a tray or pan or similar drying area and allowed to dry or is subjected to forced drying. The dried or partially dried carbonaceous material which has been so treated is then leached using water at a temperature between 0oC and 1000oC or with dilute aqueous acid or alkali between such temperatures. The leached material is then dried to form a hard compact product. The carbonaceous products so formed by this process have an altered mineral and inorganic content and good resistance to abrasion on drying. Such alteration to the inorganic and mineral content may be beneficial in processes such as combustion, gasification, carbonization, ion exchange processes and in liquefaction processes. The treatment may be adjusted so as to produce a carbonaceous material containing elements, principally metals, in intimate contact with the carbonaceous material as may be advantageous in subsequent processes. Alternatively the inorganic and mineral contents may be altered or reduced to obviate problems associated with their presence in subsequent processes.

Description

Title: The Production of Hard Compact Carbonaceous Material Through Acid/Alkali Treatment.

Suaβary of the Invention

In essence , the invention described herein involves the treatment of carbonaceous material with water or aqueous acid or aqueous alkali or a combination of these so as to produce a carbonaceous material of altered composition and in general exhibiting improved hardness and abrasion resistance. The treatment may be adjusted so as to produce a carbonaceous material contaning elements, principally metals, in intimate contact with the carboneous material as may be advantages in subsequent process.

Alternately the inorganic and mineral contents may be altered or reduced to obviate problems associated with their presence in subsequent processes. The products of this process described herein, may be produced as powdered or granular forms or they may be formed into shapes for future beneficial use.

Carbonaceous materials suffer in commercial applicaion through a lack of resistance to abrasion and through levels of inorganic or mineral constituents which are inappropriate in the final application of the carbonaceous material.

In the invention described herein carbonaceous material, including wood based material, coal, lignite, peat and like carbonaceous material, is ground to a fine state, either with or without previous drying procedures, added to water and aqueous alkali to form a paste, exhibiting gel like properties under appropriate conditions, and extruded to form pellets or applied as a slurry to a tray or pan or similar drying area and allowed to dry or is subjected to forced drying. The dried or partially dried carbonaceous material which has been so treated is then leached using water at a tempreature between 0 deg C and 1000 deg C or with dilute aqueous acid between such temperatures. The leached material is then dried to form a hard compact product.

A proportion of the carbonaceous material is removed by this process together with a proportion of the mineral and inorganic material. The carbonaceous products so formed by this process, or by similar process in which the material is subjected to acid and alkali treatment in different order or in which the products are dried or partially dried between the processing steps, have an altered mineral and inorganic content and good resistance to abrasion on drying. Such alteration to the inorganic and mineral content may be beneficial in processes such as combustion, gasification, carbonization, ion exchange processes and n 1iquefaction processesi

For example, liqnite or brown coal, treated by this process using potassium hydroxide as the alkali and leached using water alone, gave a hard_* compact carbonaceous product from the insoluble fraction _» loaded with potassium in intimate contact with the carbonaceous components of the product, rendering it suitable for processes such as gasification, where the potassium acts as a catalyst or in adsorption processes or ion exchange processes in which the potassium ions may be replaced by other ions. The hardness or abrasion resistance of this product is significantly better than briquettes or solar densified coal produced from the same coal feed. Alkali within the meaning of the above process is specifically to include carbonates.

Claims

CLAIMSThe claims defining the invention are as follows:

Claim 1. A process wherein carbonaceous material , including coal, brown coal, lignite, peat, wood or like carbonaceous material, is ground, with or without predrying, either in the presence of aqueous alkali or added to aqueous alkali, mixed and/or additionally ground and then either formed into shapes or spread as a slurry and partially or completely dried.

Claim 2. A Process wherein carbonaceous material, including coal, brown coal, lignite, peat, wood or like carbonaceous material, is ground, with or without predrying, added to aqueous acid, mixed and/or additionally ground and then either formed into shapes or spread as a slurry and partially or completely dried.

Claim 3. A Process wherein coal, brown coal, lignite, peat, wood or like carbonaceous material is treated as described in claim 1 then subjected with or without complete drying to treatment with water at a temperature in the range 0 deg C to 1000 deg C, filtered and partially or completely dried.

Claim 4. A Process wherein coal, brown coal, lignite, peat, wood or like carbonaceous material is treated as described in claim 2 then subjected to treatment with water at a temperature in the range of 0 deg C to 1000 deg C, filtered if required and partially or completely dreid.

Claim 5. A Process wherein coal, brown coal, lignite, peat, wood or like carbonaceous material is subjected to treatment as described in Clain 1 then subjected, with or without complete drying, to treatment with aqueous acid at a temperature in the range 0 deg C to 1000 deg C, filtered if required and then treated with water at a temperature in the range 0 deg C to 1000 deg C, filtered and dried.

Claim 6. A Process wherein coal, brown coal, lignite, peat, wood or like carbonaceous material is first treated as in claim 2, then subjected with or without complete drying, to aqueous alkali at a temperature in the range 0 deg C to 1000 deg C, filtered if required and then treated with water at a temperature in the range 0 deg C to 1000 deg C, filtered and dried.

Claim 7. Any process embodying all or part of any of the previous claims where in the filtrate is retained as a product.

Claim 8. Any process embodying all or part of any of the previous claims.

Claim 9. Any process embodying all or part of any previous claims in any combination.