JP2001271289A - Method for manufacturing papermaking pitch-controlling agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a pitch-controlling agent having an oil-absorbing capacity larger than that of a conventional pitch-controlling agent from papermaking sludge. SOLUTION: A method for manufacturing a pitch-controlling agent having an oil-absorbing capacity of 60-150 ml/100 g and a whiteness degree of >=60% by incinerating an inorganic pigment-containing papermaking sludge to remove combustible materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high-performance pitch control agent from wastewater from a plant for producing waste paper pulp or a paper making and coating plant.

[0002]

2. Description of the Related Art In the paper industry, waste such as sludge discharged from a plant for producing waste paper pulp or a papermaking / coating plant has been mainly disposed of by landfill. In recent years, methods of recovering and effectively utilizing energy by incineration have become widespread, but no effective use of ash has yet been established. Most of the incinerated ash can be disposed of at the cement factory as a clay raw material for cement, which has enabled large-scale disposal. However, the amount of incinerated ash that has not been used effectively is also large. In the future, incineration ash disposal costs are expected to rise, including in cement plants, and it is certain that disposal costs will squeeze paper manufacturing costs.

[0003] Wastes called papermaking sludge discharged from the papermaking industry consist of papermaking raw materials flowing out of the papermaking process, organic substances discharged from the pulp manufacturing process, and the like. In recent years, paper components, inks, and the like discharged from the waste paper pulp manufacturing process have been overwhelmingly large. Therefore, it is considered that paper sludge can be reused as a raw material for paper if its contents can be separated, and many inventions related to the use of paper sludge have been made mainly for incineration. For example, USPatent 3,765,921
No. 3 shows a method of incinerating paper sludge, pulverizing wet, drying small parts, and baking under appropriate temperature conditions to produce fine, high whiteness, low-wear calcined clay. I have. In JP-A-11-310732, sludge incineration boiler ash and RPF (Refuse Paper & Plstics Fuel) ash are reburned at 500 to 1100 ° C. using a rotary kiln or the like, and the whiteness is increased to 70% or more. And average particle size
By setting the thickness to 0.1 to 10 μm, it is indicated that the pigment is used as a papermaking pigment for coating and a papermaking pigment for internal addition.

[0004] A research report on recovered fillers states that "Krogerus, B.
et al; Use of Waste Paper Ash as Paper Filler. Da
s Papier v86-v90, 1997 "shows the results of a table test using ash as an internal filler for papermaking.

It is known that pitch troubles occur in the pulp and paper manufacturing process. Substances causing pitch trouble are brought into paper mills by using raw wood, waste paper, rosin sizing agents, etc., and are discharged from wastewater or paper-milled and taken out of the system. The causative substances remaining in the system accumulate and circulate in the system. When the circulating substances are deposited, they adhere to the paper machine and cause pitch trouble such as paper cutting. Therefore, various measures have been taken to prevent this pitch trouble. First, there are a method of reducing the amount of the causative substance brought into the papermaking system, and a method of reducing the causative substance brought into the system by adsorbing the causative substance to the adsorbent. As a method for reducing the amount of causal substances in the system, there is a method of adding an inorganic chemical called a pitch control agent to pulp. It is known that talc or the like is mainly used as the inorganic pitch control agent. But
None of the existing fillers have a sufficiently high oil absorption, except for special ones, and more oil than necessary must be used for oil absorption.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to establish a method for effectively utilizing sludge discharged from a plant for producing waste paper pulp or a paper making / coating plant.
Various uses of sludge incineration ash after energy recovery were studied. Furthermore, it relates to the technology of reusing sludge incineration ash as a pitch control agent, and the challenge is to develop a pitch control agent that is cheaper and has higher performance than conventional pitch control agents, and to reduce the amount of pitch control agent used. .

[0007]

The present invention includes a step of incinerating papermaking sludge containing an inorganic filler so as to have an oil absorption of 60 to 150 ml / 100 g to remove combustible substances and organic substances.
A method for producing a pitch control agent having a whiteness of 60% or more and incineration of paper sludge containing inorganic substances, removing combustible substances and organic substances, and neutralizing with carbon dioxide, the oil absorption of which is 60 to 15
Provided is a method for producing a pitch control agent of 0 ml / 100 g.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The particle size of the papermaking pitch control agent in the present invention is particularly preferably 1 mm or less. 1mm
It is not preferable that the ratio exceeds the limit, since the powder contacts the pitch in white water or pulp slurry containing the pitch and sediments before the pitch is sufficiently adsorbed. The lower limit of the particle size is appropriately designed depending on the type of the apparatus and the crushing conditions, but is not particularly limited.

In order to reduce the particle size of the control agent for papermaking pitch in the present invention to 1 mm or less, basically any of the following (1) to (3) is carried out.

(1) The papermaking sludge is dewatered and then dried or dried, and then pulverized and / or classified to reduce the particle size to 1 mm or less.

(2) The ash from which combustible materials have been removed by incineration has a particle size of 1 mm or less by classification and / or pulverization.

(3) The above (1) and (2) are combined. Regarding the selection of (1) to (3), or the order of classification and pulverization after selection, and the number of times for each, the properties of the obtained ash, particularly those having a required particle size of 1 mm or less, are totally reduced. It can be set appropriately according to the ratio of the occupation.

Next, the present invention will be described more specifically. Waste water from a waste paper pulp manufacturing plant or a papermaking / coating plant is concentrated by a simple sedimentation device or a coagulation sedimentation device, in which insolubles such as fibers, fillers, deinked ink, and organic matter in the form of colloidal particles are concentrated. The concentrated insoluble matter is dehydrated by a dehydrator such as a belt press, a screw press, a filter press, a decanter, and the water content is 50 to 60% by weight.
Is prepared. Since the dehydrated product is in the form of a lump having a diameter of about 10 to 50 mm, this is pulverized by a pulverizer such as a hammer mill, a vibrator kneader, a granulator pulverizer, and the particle size is 1 m.
m or less. At this time, if the pulverization cannot be performed according to the conditions, the dewatered sludge is once passed through a rotary kiln furnace at a temperature of 400 ° C. or more and 550 ° C. or less for 30 minutes to be dried, and then pulverized. As described above, unless the lump of the dewatered sludge is crushed to 1 mm or less, unburned matter remains in the lump even if it is incinerated, and a sufficiently white ash for the pitch control agent cannot be obtained. The pulverized dehydrate is incinerated in a rotary kiln furnace, fluidized bed furnace, stalker furnace, cyclone furnace, semi-dry distillation / negative pressure combustion furnace, etc. at 700 to 1000 ° C.
The organic matter is removed by incineration at a temperature of.

If the above-mentioned pulverizing treatment is not carried out, only ash which has low whiteness and cannot be used as a pitch control agent can be obtained. In this case, the ash for the pitch control agent can be obtained by grinding the ash having a low whiteness to 1 mm or less, if necessary, and then burning it in a rotary kiln at 700 to 1000 ° C. for about 0.5 to 4 hours.

In the present invention, by limiting the incineration temperature to 1000 ° C. or lower, an excellent pitch control agent having a hardness low enough to be used as a pitch control agent and having a whiteness not inferior to that of a commercially available pitch control agent is obtained. Succeeded. Burning time and burning temperature are inversely related,
If the burning temperature is lowered, the burning time must be extended, but the burning conditions in the present invention are set so that the whiteness of the ash becomes about 60% or more. In particular, in order to obtain ash having excellent oil absorption, the incineration temperature may be set to 700 ° C. to 800 ° C., and the incineration time may be set to 30 minutes to 1 hour.

After incineration, the obtained ash is pulverized using a dry pulverizer such as a jet mill or a high-speed rotary mill, or a wet pulverizer such as an attritor, a sand grinder or a ball mill. Next, the oxides in the ash produced by incineration are digested and carbon dioxide is blown in for neutralization. In the case of dry pulverization, digestion and neutralization are performed after pulverization. In the case of wet pulverization, neutralization is performed while pulverizing after digestion. Since carbon dioxide forms calcium hydroxide and calcium carbonate in the slurry, sedimentable calcium carbonate is produced. The particle size of the papermaking pitch control agent finally obtained in the present invention is 1 mm.
As a device for classifying below, a known wet or dry classifier can be applied.

The finished powder is used as a pitch control agent in the form of a slurry in each step, for example, a grinder shower water at the time of producing a GP, a white water system at the time of producing a DIP, a finished chest of each pulp, and an oxygen delignified kraft pulp. It is used at a ratio of 0.1 to 3.0% based on pulp, such as dilution water. By the way, in the case of papermaking fillers, it varies depending on the product, but 5 to 30% of pulp is added during papermaking.

As a method for producing precipitated calcium carbonate from papermaking waste, first, there is a Japanese Patent Application Laid-Open No. Hei 9-111681, which is a patent of ECC of the United Kingdom. In this method, calcium hydroxide is added to papermaking waste itself, carbon dioxide is blown into the wastewater, and the fine particles of papermaking sludge are used as nuclei to coat them, thereby producing precipitated calcium carbonate. This is different from the present invention in that the papermaking sludge is not incinerated. Also, US MINERALS TEC
HNOLOGIES INC. Has patent number PCT / US96 / 03547. It uses incinerated ash from papermaking waste. Precipitable calcium carbonate is produced using incinerated ash as a core to coat around it. At that time, similar to ECC, calcium hydroxide and incineration ash are mixed and carbon dioxide is blown into it. In the present invention, incineration ash of papermaking waste is used as a raw material, but calcium hydroxide is not newly added thereto. Therefore, this patent is clearly different from the US patent of MINERALS TECHNOLOGIES.

Further, the conventional patent is for producing a pigment used in an internal filler for papermaking or a paint for coating from paper ash sludge incineration ash, but the present invention only relates to the production of a pitch control agent for papermaking. Things.

[0020]

EXAMPLES Example 1 Paper sludge discharged from a paper mill was dried in a rotary kiln furnace at 400 ° C. for 30 minutes.
It was pulverized to a particle size of 1 mm or less with a granulator (Granulator RGS-1512, manufactured by Kurimoto Iron Works, Ltd.).
Thereafter, incineration was performed at a predetermined temperature and time using a rotary kiln furnace. The ash obtained after the incineration treatment was neutralized with carbon dioxide while being wet-ground with a sand grinder (1/2 gallon sand grinder manufactured by Inoue Seisakusho Co., Ltd.). The oil absorption and whiteness of the obtained product were confirmed.

As shown in Table 1 as a reference example, a pitch control agent having a much higher oil absorption than calcined kaolin and talc and having an oil absorption similar to that of white carbon could be produced.

The incineration temperature is 700-800 ° C. and the incineration time is 0.5
The pitch control agent with the highest oil absorption was obtained in about 4 hours.

[0023]

[Table 1]

[Example 2] In Example 1, 800 ° C, 1
After being incinerated for an hour, the product was dry-pulverized by a jet mill (manufactured by Seishin Enterprise Co., Ltd., STJ-200), digested and neutralized with carbon dioxide. Table 2 shows the analysis results of the pitch control agent. Although the whiteness is lower than that of commercially available talc, the whiteness can be sufficiently used as a pitch control agent. Although the wire abrasion is considerably higher than that of commercially available talc, it is a value that is not a problem as a pitch control agent.

[0025]

[Table 2]

[Example 3] A low-tap sieve shaker in which the incinerated ash neutralized with carbon dioxide of Example 2 is set with a stainless sieve having a nominal size of 1 mm (16 mesh) specified in JIS Z 8801-1994. To obtain a sample of 1 mm or less. The performance of this sample as a pitch control agent was measured by a sticky substance transfer test. Adhesive transfer test-vinyl acetate An experiment was performed using vinyl acetate (Sibinol PZ-804, manufactured by Seiden Chemical Co., Ltd.) as a model adhesive component. Vinyl acetate was dry-pulverized and dispersed in the samples. (1) First, vinyl acetate powder was prepared.

The adhesive (sacbinol for bag making) containing vinyl acetate as a main component was dried to remove the solvent, and the dried vinyl acetate was finely pulverized by freeze-pulverization. After drying under reduced pressure, 3 g was mixed well with 1 g of microcrystalline cellulose (Avicel SF) in a mortar.

By sieving, a mesh path having a diameter of 355 μm, 75 μm
The m-on fraction was used as a sample. (2) To 0.5% slurry of 0.5g of GP (pulp for papermaking),
Ash and talc were added in predetermined amounts, respectively, and the vinyl acetate particles prepared in (1) were dispersed and treated under the following conditions.

The amount of the pitch control agent added is as large as 20% to 80% based on the pulp, because the adhesive component is added.

Reaction conditions: 40 ° C., 30 minutes, 200 rpm Chemical addition amount: 0.1 g, 0.2 g, 0.3 g, 0.4 g Vinyl acetate powder: 0.027 g (0.02 g as vinyl acetate) Dry (3) Collect solids Then, the adhesive substance was transferred to black paper by hot pressing. The treated slurry was filtered through No. 2 filter paper, and the solid content on the filter paper was dried. Heat to 105 ° C (15 minutes) between plates and black paper, pressurize with a press (20 kg / cm ² , 5
Minute). (4) The transferred sticky foreign matter was measured with a scan mark (Dart Analyzer image analyzer manufactured by Diatron Co., Ltd.). The adhesive itself is translucent, but
The contrast was clear because the fibers were stripped and transferred to black paper. The image was subjected to a reversal process, the detection range was set to a foreign substance area of 0.05 mm ² or more, and the total number of adhesive transfer of one sheet was counted. (The threshold value is fixed at 50.) The tabulated results are shown in Table 3 and FIG. Thus, the pitch control agent manufactured from the incinerated ash was more effective than the commercially available pitch control talc.

[0031]

[Table 3]

Comparative Example 1 Incineration temperature 550 ° C., incineration time 2
When the same incineration as in Example 1 was performed at hr, the oil absorption was only 50 ml / 100 g and the whiteness was only 40.0. The results are shown in Table 1.

Comparative Example 2 Incineration temperature 1100 ° C., incineration time 1
When the same incineration as in Example 1 was performed at hr, the oil absorption amount was 80 ml / 100 g and the whiteness was 75.0, but only the oil absorption amount and the whiteness were very poor. The results are shown in Table 1.

[Comparative Example 3] The same papermaking sludge as in Example 1, which had not been pulverized, was incinerated at an incineration temperature of 800 ° C and an incineration time of 2 hours. Oil absorption 55110ml / 100g, whiteness
55 ashes were obtained. The results are shown in Table 1.

[Brief description of the drawings]

FIG. 1 is a graph showing the effect of incineration ash on the number of vinyl acetate particles transferred.

Continued on the front page F term (reference) 4D059 AA30 BB01 BB11 BB13 BB14 BB15 BE08 BE16 BE31 BF15 BK11 BK30 CC10 EB20 4L055 AG14 AH01 BC01 EA02 EA10 FA06

Claims (3)

[Claims] 1. An oil absorption method comprising the steps of burning papermaking sludge containing an inorganic filler to remove combustibles, and pulverizing and / or classifying ash obtained by removing combustibles. Is a pitch control agent having a whiteness of 60% or more and a whiteness of 60% or more. 2. A paper pitch control agent having an oil absorption of 60 to 150 ml / 100 g, comprising neutralizing the incinerated ash obtained by the incineration of claim 1 with carbon dioxide after removing combustibles. Production method. 3. The papermaking sludge is dewatered and then dried or dried, and then pulverized and / or classified to a particle size of 1 m.
The method according to claim 1 or 2, wherein the incineration is performed after the temperature is reduced to m or less.