US 12,606,487 B2 · Method for preparing concrete based on GGBS, silicon-aluminum compounds and CO2 waste gas

Abstract

A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO2 waste gas includes: putting a certain quantity of GGBS, silicon-aluminum compounds and water into a ball milling tank; introducing CO2 waste gas into the tank, and stopping the introduction when gas pressure in the tank reaches a standard; and starting the ball milling tank, and repeating the gas charging and ball milling for multiple times until a median size reaches the standard and CO2 is completely reacted and adsorbed by the GGBS, and finally preparing concrete from a GGBS mixture meeting requirements. According to the method, by adding the silicon-aluminum compounds into the GGBS, and under a mechanical action of the ball milling machine, the GGBS is promoted to react with and adsorb CO2.

A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO2 waste gas, comprising the following steps:

(1) mixing the GGBS, the silicon-aluminum compounds and distilled water in a mixer, and putting into a ball milling tank with aluminum oxide as a ball milling medium;
(2) introducing, by using an inflator pump, CO2 waste gas into the ball milling tank, and turning off the inflator pump when gas pressure in the tank reaches 190-210 kPa;
(3) starting a ball milling machine, milling at a speed of 400-600 rpm for 10 to 20 min, then standing still, repeating operations in step (2), then continuing the milling, and repeating the operations for multiple times until a specified mass M of CO2 waste gas is introduced, filling the tank with nitrogen until the gas pressure in the tank reaches 190-210 kPa, and controlling, by using an air cooling machine, a temperature of the ball milling tank to be 20±2° C.;
wherein the specified mass M of CO2 waste gas is mCO2,
m
CO
2
=
xN
1
.
1
⁢
1
⁢
2
+
0
.
7
⁢
1
⁢
8
⁢
(
M
-
x
)
,
M
=
∑
m
n
⁢
K
n
,
in the formula, x is the mass of the industrial waste gas with the highest CO2 content in the CO2 waste gas;
N indicates a proportion of CO2 in the industrial waste gas with the highest CO2 content in the CO2 waste gas;
χN/1.112 indicates the mass of CO2 in the industrial waste gas with the highest CO2 content in the CO2 waste gas;
M is the mass of the waste gas introduced into the tank, and is also the total mass of all industrial waste gases in the CO2 waste gas;
and 0.718(M−χ) is a sum of CO2 content of other industrial waste gases in the CO2 waste gas, mn is the separate mass of each industrial waste gas, and Kn is a proportion of CO2 in each industrial waste gas;
(4) measuring a median size of a mixture of GGBS and silicon-aluminum compounds, and if the median size is larger than 9.2 micrometers, continuing the ball milling in nitrogen until the median size is obtained as 8.8-9.2 micrometers;
(5) mixing the mixture of GGBS and silicon-aluminum compounds obtained in step (4) with Portland cement to obtain a GGBS-cement mixture, adding water according to a mass ratio of water to GGBS-cement mixture of (0.35-0.41):
1, and mixing with a coarse and fine aggregate to obtain a slag concrete;
and
(6) pouring the slag concrete obtained in step (5) into a mold, vibrating to compact, then sealing the mold, curing for 24 h at a temperature of 22±2° C. and a relative humidity greater than or equal to 90%, and demoulding;
wherein in step (1), when the mass of GGBS is known, the mass of silicon-aluminum compounds added into the ball milling tank is calculated according to the following formula:
m
SA
=
SSA
SA
SSA
S
×
ω
×
(
m
S
-
m
CaO
-
m
MgO
)
,
in the formula, mSA is the mass of silicon-aluminum compounds;
SSASA and SSAS are specific surface areas of the silicon-aluminum compounds and the GGBS, respectively;
a value range of ω is 0.843-0.951;
mS is the mass of GGBS;
mCaO is a total mass of calcium oxide in the mixture of GGBS and silicon-aluminum compounds;
and mMgO is a total mass of magnesium oxide in the mixture of GGBS and silicon-aluminum compounds.

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Method for preparing concrete based on GGBS, silicon-aluminum compounds and CO2 waste gas

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Method for preparing concrete based on GGBS, silicon-aluminum compounds and CO2 waste gas

Life of this patent

Abstract

Claims7