AU2018101200A4

AU2018101200A4 - Production of environmentally sustainable bricks & blocks and plaster for construction from coastal desert sands and fly ash

Info

Publication number: AU2018101200A4
Application number: AU2018101200A
Authority: AU
Inventors: Peter Anil Rodricks
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-19
Filing date: 2018-08-19
Publication date: 2018-09-20
Anticipated expiration: 2026-08-19

Abstract

A method for the production of Bricks & Blocks and Construction Plaster utilising carbonate rich coastal desert sand calcined in rotary kiln to produce high purity Lime (CaO) and Silica - and waste fly ash from thermal power production, resulting in environmentally sustainable material to mitigate the use of scarce natural sands. Figure 1 illustrates the Thermogravimetric Analysis of Desert Sand Fig 1 692.41*C 1.5 -1 R.0 - --2 70- 796"C 0.5- -3 60- .- 4 0 200 400 600 800 1000 E- Up Temperature (*C) Fig 2 illustrates the Calcination temperature chart used to achieve -99.9% calcination of Calcium Carbonate to Calcium Oxide Fig 2 --- 2 737"C \ 781 *C F - ~750*C\i -100 i 798"C 90 21 90- 2 .4 i% --4 Rodricks Sand 2. 5"C/min 2E.02% 80- Rodricks Sand 1, 5"C/min 30.27% Rodricks Sand 1, 10*C/min -5 Rodricks Sand 1, 2.5*C/min -6 0 200 400 600 800 1000 Ex Up Temperature ("C)

Description

Editorial Note 2018101200

There are five pages of description only

ENVIRONMENTALLY SUSTAINABLE BRICKS & BLOCKS AND CONSTRUCTION PLASTER FROM CALCINED CARBONATE RICH DESERT SAND AND FLY ASH

FOR CONSTRUCTION BACKGROUND OF INVENTION: [0001] There is an acute global shortage of sand for construction purposes leading to widespread environmental degradation and illegal exploitation of natural river and marine sands. Directly related is the large volumes of fresh water used to process these sands prior to their use in construction to cleanse them of silt and salts. The continued widespread use of fired clay bricks and construction forms also results in the loss of topsoil and increased C02 emissions. This invention aims to mitigate these problems through the use of alternative and waste materials.

[0002] Consistent with the geology of coastal deserts, sands can contain high concentrations of Calcium Carbonate in the form of sedimentary sandstone. These carbonate rich sands are both abundant and logistically accessible without the extensive infrastructure associated with mining and quarrying and can be processed through existing technology already used in the cement industry. This geological phenomenon is therefore a key basis for this invention.

[0003] Fly Ash from thermal power plants continues to be produced globally as a waste product in great quantities, about half of which are not recycled. International Energy Agency forecasts indicate that thermal power will remain a significant source of electricity by 2030 - thus the need for fly ash recycling will continue well into the future.

[0004] This invention will enable governments and the construction industry develop a sustainable alternative to quarried, river and marine sands for the production of Bricks & Blocks and Construction Plaster with significant environmental benefits. A key additional benefit is the recovery of waste C02 and commercial production of liquid C02 from the calcination process for the food industry, Enhanced Oil Recovery (EOR) and/ or efficient C02 sequestration to benefit the environment. Much of the research has centered on the Middle-East where carbonate rich desert sand, related raw materials inputs and commercial potential are optimal for production projects. DESCRIPTION OF PRODUCTION PROCESS: [0005] This invention relates to the manufacturing method of Bricks & Blocks and Construction Plaster from calcined carbonate rich coastal desert sands and waste fly ash from thermal power plants, with the added environmental benefit of C02 recovery and sequestration.

[0006] This invention enables Zero Emissions by C02 capture and commercialization in the base material production process. By integrating the production of calcined sand production with Fly Ash Bricks & Blocks production, heat from LNG/LPG combustion in kiln and from the calcination process can be utilized for steam generation for Autoclave curing process of bricks and blocks. MANUFACTURE METHOD: [0007] Base material is produced by the calibrated calcination of carbonate-rich desert sand in a Rotary kiln to achieve -99.9% calcination of Calcium Carbonate (CaC03) to Lime (CaO). Said production method results in material without sintering or agglomeration effects. Calcined Sand retains the original finely divided state of raw desert sand, eliminating additional crushing processes enabling immediate on-site utilization or transportation. The composition of fully calcined material is Silica, high purity

Lime (CaO) and trace elements common in raw material for cement manufacture.

[0008] Detailed Calcination Process: Thennogravimetric analysis (TGA) of desert sand to determine physical conditions of calcination followed by calcination in rotary kiln set at 4-5 RPM. Complete conversion of the calcium carbonate content of the sand is achieved at 900 °C in a one (1) hour residence time.

[0009] Tests on calcined sand show no deleterious presence of Sugars, Sulphates or Chlorides in Base material.

[0010] The Calcination tests and confirmation of process were conducted on behalf of the inventor by Australian Nuclear Science and Technology Organisation, Lucas Heights Science and Technology Centre (ANSTO), Sydney, Australia. Desert sand sample used for the invention is from the A1 Khawaneej area of Dubai, UAE.

[0011] Bricks & Blocks production method: The calcined material from the above process is mixed with Class F fly ash, manufactured sand from crushed rock, Cement and water to produce bricks and blocks for construction. Proportions of mixture are as follows: Calcined desert sand 22.6%

Class F fly ash 22.6%

Crushed rock sand 22.6%

Cement 7.5%

Water 24.7%

After mixing and casting, the bricks are stripped and cured as per AS 1012.8.3 for 7 days. Compressive strength is tested to be 11.5 MPa [0012] Construction Plaster: Calcined sand is thoroughly mixed with Portland cement at 5:1 ratio and water added to a workable consistency. This results in a surface coating construction plaster of high quality, white, hard and smooth texture. The high purity of finely divided Fime in calcined sand enables the production of low cement plaster in a simple and efficient process resulting in the complete elimination of quarried or natural sands.

[0013] C02 is produced in the Calcination process and combustion of LPG and/or LNG in rotary kiln in industrially pure and viable volumes without intensive scrubbing.

[0014] General Notes: Kiln, Fly Ash bricks & blocks plant and C02 liquefaction plants are standard industrial plants used in construction and allied industries.

Autoclave = Steam chamber with variable temperature and pressure used to accelerate curing process of bricks/ blocks. EOR = Enhanced Oil Recovery process whereby liquid C02 is pumped into secondary injection well to increase production from partially depleted oil wells; pumped C02 being permanently sequestered underground.

[0015] Research and testing on behalf of the inventor were conducted by: - Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights Science and Technology Centre - Boral Material Technical Services Baulkham Hills Laboratory - SGS Australia, Perth.

Claims

1. Method of Integrated Manufacture of Bricks & Blocks from calcined sand from coastal deserts and fly ash.

2. Method of manufacture of Construction Plaster from calcined sand from coastal deserts and Portland cement eliminating the use of quarried and natural sands.