JP5797976B2 - Method for synthesizing lithium zeolite - Google Patents

Description

  The present invention mainly relates to a method for synthesizing lithium zeolite.

  Zeolite is an aluminosilicate-based crystalline compound, and is a wide variety. There are various industrial utilization methods of zeolite, and utilization methods such as a catalyst, a humidity control material, a molecular sieve, an adsorbent, and an ion exchanger can be mentioned. Applications differ if the composition and crystal structure of the zeolite are different.

  It is also known that lithium zeolite is useful as an admixture for concrete (Patent Document 1, Patent Document 2, Patent Document 3).

  On the other hand, in China and Vietnam, effective use of industrial by-products is strongly demanded in each industry. One example is the effective use of petroleum refining catalyst residues, and we are struggling to develop its use.

The catalyst residue for petroleum refining is a SiO ₂ —Al ₂ O ₃ based material containing moisture and organic matter. Since it contains organic substances derived from petroleum, it is difficult to handle and has restrictions on ingredients, so no effective utilization method has been found.

By the way, zeolite is a kind of aluminosilicate and is also a SiO ₂ —Al ₂ O ₃ based material. From the component point of view, it is similar to petroleum refining catalyst residues.

  Therefore, if petroleum refining catalyst residue can be used as a raw material for synthetic zeolite, it is important from the viewpoint of effective utilization of by-products and from the viewpoint of cost reduction of synthetic zeolite.

  However, petroleum refining catalyst residues cannot be used as raw materials for lithium zeolite synthesis.

In view of the effective utilization of petroleum refining catalyst residues, we have conducted various studies, and as a result, by treating SiO ₂ —Al ₂ O ₃ based material obtained by heat treatment at a specific temperature with an aqueous lithium hydroxide solution, It was discovered that lithium zeolite can be synthesized efficiently.

JP 2008-297137 A JP 2009-12989 A JP 2009-78939 A

  Provided is a method for efficiently synthesizing lithium zeolite by using a petroleum refining catalyst residue for which no effective utilization method has been found.

The present invention comprises (1) heat treatment of a petroleum refining catalyst residue at 350 ° C. or higher and 950 ° C. or lower, and the SiO ₂ component is 40 to 55%, the Al ₂ O ₃ component is 40 to 55%, R ₂ O (Na ₂ the total amount of O and _{K 2} O) is less than 1%, loss on ignition of SiO ₂ -Al ₂ O ₃ -based material is 1% or less, and wherein the treatment with aqueous lithium hydroxide A method for synthesizing lithium zeolite, and (2) a method for synthesizing lithium zeolite, wherein the treatment temperature in a lithium hydroxide aqueous solution is 10 ° C. to 80 ° C.

  The lithium zeolite production method of the present invention not only enables effective utilization of petroleum refining catalyst residues, but also enables efficient synthesis of lithium zeolite, and uses the lithium zeolite obtained by this method as a cement admixture. Thus, the present invention has effects such as exhibiting remarkable effects in suppressing cracks in cement concrete and suppressing alkali silica reaction (ASR).

Hereinafter, the present invention will be described in detail.
In the present invention, “parts” and “%” are based on mass unless otherwise specified.

The lithium zeolite will be described.
Among lithium zeolites, a lithium zeolite having a Si / Al atomic ratio of 1 is preferable because it has a large effect of suppressing the alkali silica reaction. Examples of lithium zeolite having an Si / Al atomic ratio of 1 include EDI type, ABW type, and LTA type.

The EDI-type zeolite is a general term for zeolites having a structure similar to a compound called Edingtonite. Edintonite is generally represented by Ba ₂ Al ₄ Si ₆ O ₂₀ · 8H ₂ O. The lithium-containing EDI-type zeolite corresponds to a compound in which Ba in the above Edintonite is replaced with Li. Therefore, it is represented by the general formula Li ₄ Al ₄ Si ₆ O ₂₀ · nH ₂ O. N in the formula is 6-10.

ABW-type zeolites containing lithium were named after being first reported by Barrer and White (Barrer RM and White ED, J. Chem. Soc., 1951, 1267). . That is, it is often written as A (BW) in the meaning of A of zeolite found by Barrer and White. Here, the meaning of A will be supplemented. A is the first letter of the alphabet, meaning “found first” (respect: nomenclature and structure of zeolite, catalyst, Vol. 40, No. 3, pp. 185-190, 1998). ABW-type zeolite containing lithium has about 15 to 25% of crystal water. The SiO ₂ content and the Al ₂ O ₃ content are about 30 ± 5%, respectively.

The lithium zeolite of the present invention includes those obtained by heat treating lithium zeolite.
The heat treatment temperature varies depending on the zeolite. For example, in the case of EDI type, it is preferable that it is 200-700 degreeC. When the lithium-containing EDI-type zeolite is heat-treated at 200 to 700 ° C., it changes into an amorphous substance. That is, the crystal structure of the EDI-type zeolite is maintained up to 200 ° C., and the crystal changes from amorphous to 200 ° C. or more. And although it is in an amorphous state up to 700 ° C., when it exceeds 700 ° C., it crystallizes and changes to eucryptite.

In the case of the ABW type, 300 to 650 ° C. is preferable. When the ABW-type zeolite containing lithium is heat-treated at 300 ° C. to 650 ° C., it changes to an anhydrous ABW-type zeolite. That is, the crystal structure of the ABW type zeolite is maintained up to 300 ° C., and when the temperature exceeds 300 ° C., the crystal structure changes to a completely different crystal structure to become an anhydrous ABW type zeolite. And it is in the state of anhydrous ABW type zeolite up to 650 ° C., but when it exceeds 650 ° C., it changes to γ-eucryptite. And when it heats further, it changes to (beta) -eucryptite at 900-1000 degreeC.
If the heat treatment conditions are not within the above temperature range, there may be a case where a sufficient effect of suppressing expansion due to alkali-silica reaction or a salt damage suppressing effect cannot be obtained.

The heat treatment referred to in the present invention is not particularly limited, but usually means a treatment such as drying or baking.
As a specific method, for example, a catalyst obtained by heating a petroleum refining catalyst residue at 350 ° C. to 950 ° C. is reacted in a lithium hydroxide aqueous solution to form lithium zeolite, followed by a drying operation step. Thus, the predetermined heat treatment may be performed, or after drying once under a condition of less than 200 ° C., the heat treatment may be performed again under the predetermined condition.
The time for the heat treatment is not particularly limited, but is preferably about 5 minutes to 24 hours, and more preferably 10 minutes to 12 hours. If the reaction time is less than 5 minutes, the reaction in which the EDI-type zeolite changes to an amorphous substance or the reaction in which the ABW-type zeolite changes to anhydrous ABW may not proceed sufficiently. It may become.

  The drying device is not particularly limited, and a drum dryer, a shelf dryer, a cylindrical dryer, a rotary kiln, an electric furnace, or the like can be used.

The lithium content of the lithium zeolite of the present invention is not particularly limited, but is usually preferably 5% or more and more preferably 7% or more in terms of Li ₂ O. The maximum amount of lithium that can be supported can be calculated as 13.5% from the theoretical value at which the Si / Al molar ratio is 1.
When the lithium content is less than 5%, when used as a concrete admixture, a sufficient effect of suppressing the alkali silica reaction may not be obtained.

The content of sodium or potassium in the lithium zeolite of the present invention is not particularly limited, but usually the total amount of Na ₂ O and K ₂ O is preferably 0.5% or less, 0.3% The following is more preferable. When the total amount of Na ₂ O and K ₂ O exceeds 0.5%, there may be a case where a sufficient effect of suppressing expansion due to the alkali silica reaction cannot be obtained.

The specific surface area of the lithium zeolite of the present invention is not uniquely determined and is not particularly limited, but is usually in the range of ² to 200 m ² / g in terms of BET specific surface area.

The petroleum refining catalyst residue referred to in the present invention contains a SiO ₂ component and an Al ₂ O ₃ component as main components and contains moisture and organic matter. The SiO ₂ —Al ₂ O ₃ -based material obtained by heat-treating this petroleum refining catalyst residue at 350 ° C. or more and 950 ° C. or less is useful as a starting material when synthesizing lithium zeolite. In the case of heat treatment under conditions of less than 350 ° C. or more than 950 ° C., it is not useful as a starting material when synthesizing lithium zeolite.

When a petroleum refining catalyst residue is heat-treated at 350 ° C. or higher, the crystallinity gradually becomes unclear and becomes amorphous. In the temperature range of 950 ° C. or lower, the amorphous state is maintained, but when it exceeds 950 ° C., it crystallizes and changes to mullite (3Al ₂ O ₃ .2SiO ₂ ) and silica to be stabilized.

  In the present invention, although the petroleum refining catalyst residue is heat-treated, the heat treatment method is not particularly limited. Specific examples thereof include a method using a shaft kiln, rotary kiln, wall furnace, tunnel furnace, electric furnace, muffle furnace, and the like. In particular, heat treatment in a rotary kiln is suitable. The heat treatment temperature must be 350 ° C. or higher and 950 ° C. or lower.

It can be used as a starting material when synthesizing lithium zeolite by preparing a SiO ₂ —Al ₂ O ₃ -based material obtained by heat-treating a petroleum refining catalyst residue at 350 ° C. or more and 950 ° C. or less to a specific particle size.
Fineness in this case, the Blaine specific surface area value (hereinafter, referred to as Blaine value) is preferably 3,000~9,000cm ² / g, the more preferably 4,000~8,000cm ² / g, 5,000~ Most preferred is 7,000 cm ² / g. If it is less than 3,000 cm ² / g, the production efficiency of lithium zeolite is poor, and even if the fine powder exceeds 9,000 cm ² / g, further enhancement of the effect cannot be expected. May tend to be bad.

The SiO ₂ —Al ₂ O ₃ -based material obtained by heat-treating the catalyst residue of petroleum refining at 350 ° C. or higher and 950 ° C. or lower has a SiO ₂ component of 40 to 55%, an Al ₂ O ₃ component of 40% to 55%, R ₂ O is preferably 1% or less, and the ignition loss is preferably 1% or less.

There is no SiO ₂ component of less than 40% or Al ₂ O ₃ component of more than 55%. This is because it depends on the composition of the catalyst used in petroleum refining. If the SiO ₂ component exceeds 55% or the Al ₂ O ₃ component is less than 40%, the production efficiency of lithium zeolite may deteriorate.

R ₂ O means the total amount of Na ₂ O and K ₂ O, and is calculated by the following formula.
_{R 2 O = Na 2 O +} 0.658K 2 O
In the present invention, it is important that R ₂ O is 1% or less. R ₂ O is preferably 0.7% or less, and more preferably 0.5% or less. When R ₂ O exceeds 1%, the resulting lithium zeolite may not have a sufficient alkaline silica reaction inhibitory effect.

The loss on ignition of the SiO ₂ —Al ₂ O ₃ -based material obtained by heat-treating the petroleum refining catalyst residue at 350 ° C. or more and 950 ° C. or less is preferably 1% or less, and 0.7% or less. More preferred is 0.5% or less. When the ignition loss exceeds 1%, the lithium zeolite production reaction is inhibited, the reaction time becomes longer, and the efficiency may be deteriorated.

In the present invention, the conditions for treating the SiO ₂ —Al ₂ O ₃ -based material obtained by heat treating the petroleum refining catalyst residue with an aqueous lithium hydroxide solution are not particularly limited, but the temperature is usually 10 ° C. -80 ° C is preferable, and 20 ° C-70 ° C is more preferable. If the temperature is less than 10 ° C, the reaction time may be long and the efficiency may be deteriorated. If the temperature is higher than 80 ° C, a special sealed container such as a pressure-resistant container may be required. The reaction time is preferably 30 minutes to 24 hours, and more preferably 1 hour to 12 hours. If it is less than 30 minutes, the reaction may not proceed sufficiently, and even if it exceeds 24 hours, further enhancement of the effect cannot be expected.
The concentration of lithium hydroxide is preferably 0.05 mol / liter to 2 mol / liter, and more preferably 0.1 mol / liter to 1 mol / liter. If it is less than 0.05 mol / liter, the amount of lithium supported may be small, and if it exceeds 2 mol / liter, further enhancement of the effect cannot be expected.
Lithium zeolite includes Li-LTA type, ABW type and EDI type. The higher the reaction temperature and the longer the reaction time, the easier it is to produce Li-LTA and ABW types. The EDI type is easy to stabilize under conditions where the temperature is low and the reaction time is short.

  Hereinafter, although an example and a comparative example are given and the contents are explained in detail, the present invention is not limited to these.

<Synthesis of lithium zeolite>
Lithium zeolite was synthesized by reacting the catalyst residue of petroleum refining with heat and lithium hydroxide as a raw material in water.
At this time, the Li ₂ O / Al ₂ O ₃ molar ratio was 2.0, the reaction temperature was 60 ° C. or 80 ° C., the reaction time was 12 hours, and the reaction was conducted while stirring.
The obtained composite was separated into solid and liquid, washed with warm water at 60 ° C., and dried at 70 ° C.
10 kg of heat-treated petroleum refining catalyst residue was used, and lithium hydroxide was used after being dissolved in water. The lithium hydroxide solution was 100 kg. Table 1 shows the results of identification of the synthesized product by powder X-ray diffraction (XRD).

<Materials used>
(A) Heat-treated petroleum refining catalyst residue A: Heat-treated at 300 ° C.
SiO ₂ component% 49, Al ₂ O ₃ component 45%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O% 0.7%, ignition loss 2.5%, other 0.8%.
(B) Heat-treated petroleum refining catalyst residue B: Heat-treated at 350 ° C.
SiO ₂ component 50%, Al ₂ O ₃ component 46%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O 0.7%, ignition loss 1.0%, other 0.3%.
(C) Heat-treated petroleum refining catalyst residue C: Heat-treated at 500 ° C.
SiO ₂ component 50%, Al ₂ O ₃ component 46%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O 0.6%, loss on ignition 0.7%, others 0.7%.
(D) Heat-treated petroleum refining catalyst residue D: Heat-treated at 700 ° C,
SiO ₂ component 50%, Al ₂ O ₃ component 46%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O 0.7%, ignition loss 0.6%, others 0.7%.
(E) Heat-treated petroleum refining catalyst residue E: Heat-treated at 900 ° C
SiO ₂ component 50% _Al 2 _{O 3} component 46% _Fe 2 _{O 3} component 1% CaO component _{1%, R 2 O% 0.6} %, loss on ignition 0.5%, other 0.9%.
(F) Heat-treated petroleum refining catalyst residue F: Heat-treated at 950 ° C
50% SiO ₂ component, 46% Al ₂ O ₃ component, 1% Fe ₂ O ₃ component, 1% CaO component, 0.5% R ₂ O, 0.5% loss on ignition, 1.0% other.
(G) Heat-treated petroleum refining catalyst residue G: Heat-treated at 1000 ° C.
50% SiO ₂ component, 46% Al ₂ O ₃ component, 1% Fe ₂ O ₃ component, 1% CaO component, 0.5% R ₂ O, 0.5% loss on ignition, 1.0% other.
(H) Heat treatment of petroleum refining catalyst residue H: Heat treatment at 700 ° C.,
SiO ₂ component 50%, Al ₂ O ₃ component 46%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O 2%, ignition loss 0.5%, others 0.3%.
(I) Heat-treated petroleum refining catalyst residue I: Heat-treated at 700 ° C,
SiO ₂ component 40%, Al ₂ O ₃ component 55%, Fe ₂ O ₃ component 1%, CaO component 1%, R ₂ O 0.5%, ignition loss 0.5%, other 0.1%.
(J) Heat treated petroleum refining catalyst residue J: Heat treated at 700 ° C.,
SiO ₂ component 55% _Al 2 _{O 3} component 40% _Fe 2 _{O 3} component% CaO _component%, R 2 _O0.5%, loss on ignition 0.5%, other 0.1%.
Lithium hydroxide: reagent grade 1.

From Table 1, it can be seen that the SiO ₂ —Al ₂ O ₃ -based material obtained by heat-treating a petroleum refining catalyst residue at 350 ° C. or more and 950 ° C. or less is suitable as a starting material when synthesizing lithium zeolite. When the reaction temperature was 60 ° C., it was EDI type zeolite. When the reaction temperature was 80 ° C., it was ABW type zeolite.

  According to the method for synthesizing lithium zeolite of the present invention, lithium zeolite can be efficiently synthesized. In addition, effective utilization of petroleum refining catalyst residues, for which no effective utilization method has been found so far, can also be carried out.

Claims (2)

40 to 55% by mass of SiO ₂ component, 40 to 55% by mass of Al ₂ O ₃ component, R ₂ O (Na ₂ O) obtained by heat-treating a catalyst residue of petroleum refining at 350 ° C. or more and 950 ° C. or less. And a K ₂ O total amount) of 1 mass% or less, and a loss of ignition is 1 mass% or less, a SiO ₂ —Al ₂ O ₃ -based material is treated with an aqueous lithium hydroxide solution. Synthesis method. The process temperature in lithium hydroxide aqueous solution is 10 to 80 degreeC, The synthesis method of the lithium zeolite of Claim 1 characterized by the above-mentioned.