CN115321716A - Titanium white wastewater treatment method - Google Patents

Abstract

The invention discloses a method for treating titanium dioxide wastewater, which comprises the following steps: (1) mixing lime with industrial water to prepare a mixed solution; (2) adding the mixed solution into titanium dioxide wastewater for neutralization; (3) And (4) filtering by using a plate frame, removing impurities, and recycling or discharging the treated water. The method changes the reclaimed water for dissolving lime into industrial water, so that the consumption of raw materials can be reduced, and the effective utilization rate of the raw materials can be improved.

Description

Titanium white wastewater treatment method

The technical field is as follows:

the invention relates to a wastewater treatment method, in particular to a titanium dioxide wastewater treatment method.

Background art:

in the actual production, the acid wastewater generated in the production of titanium dioxide by a sulfuric acid method is treated by a limestone neutralization method, sulfate ions and heavy metal ions in water can be effectively removed, the pH value of the water is adjusted, the equipment investment requirement is low, the treatment process is simple and easy to implement, the system maintenance is convenient, the treated water amount is large, and the treatment process is mature. However, the existing process still has a plurality of defects, and the water treatment workshop mainly uses the following raw materials: the lime and carbide slag are most alkaline, and the alkalinity of the white mud, the dust collecting ash and the stone powder is weakened in sequence. At present, the liquid used for dissolving or participating in the reaction is reclaimed water, and the reclaimed water is clear liquid obtained by neutralizing and pressing wastewater by a plate frame. However, the consumption of lime for water treatment is high, and the cost of lime is high, so that the cost of wastewater treatment is high.

The invention content is as follows:

in order to reduce the consumption of raw materials and improve the effective utilization rate of the raw materials, the invention provides a method for treating titanium white wastewater, which can reduce the consumption of the raw materials and improve the effective utilization rate of the raw materials.

A method for treating titanium dioxide wastewater comprises the following steps:

(1) Mixing lime and industrial water to prepare a mixed solution;

(2) Adding the mixed solution into titanium dioxide wastewater, and neutralizing;

(3) And (4) filtering by using a plate frame, removing impurities, and recycling or discharging the treated water.

Preferably, the pH value of the industrial water is 8.6.

Preferably, the pH value of the titanium dioxide wastewater is 2-3.

The solubility of the reclaimed water to the lime is lower than that of the industrial water to the lime; reaction of the recycled water with lime produces a small portion of precipitate. Firstly, water reacts with lime to generate calcium hydroxide, the calcium hydroxide is slightly soluble in water (0.15 g of calcium hydroxide is dissolved in 100ml of water at normal temperature), and the unit molar mass of the calcium hydroxide is heavier than that of calcium oxide, so that the mass of dried filter residue is heavier than that of dissolved lime; secondly, at low pH, the medium water is less soluble than the industrial water in lime and produces more filter residue.

Has the beneficial effects that:

the application discloses a treatment method of titanium dioxide wastewater, which changes the dissolving water of lime from reclaimed water to industrial water, reduces the consumption of raw materials and improves the effective utilization rate of the raw materials.

The specific implementation mode is as follows:

the invention is further illustrated by the following examples of some representative compounds, which are not intended to limit the invention.

Example 1

According to the experience of wastewater treatment and the components and physicochemical properties of raw materials and reclaimed water, the water treatment workshop carries out multiple groups of related experimental researches on reclaimed water, industrial water (tap water) and lime.

TABLE 1

1. Under a certain volume, the pH value of industrial water is 0.7 higher than that of reclaimed water; when the Baume degree is 9, the amount of lime consumed by industrial water is 5.06g more than that consumed by reclaimed water; filtering the prepared lime milk respectively, and drying the filter residue to obtain almost the same weight.

2. By configuring the lime milk with the Baume degree of 9, it can be inferred that the industrial water is easier to dissolve lime than the reclaimed water;

3. deducing by comparing the weight of the dried filter residue with the consumption data of lime, wherein 1) the solubility of the water in the filter residue to the lime is lower than that of the industrial water to the lime; 2) Reaction of the recycled water with lime produces a small portion of precipitate. Reason analysis: firstly, water reacts with lime to generate calcium hydroxide, the calcium hydroxide is slightly soluble in water (0.15 g of calcium hydroxide is dissolved in 100ml of water at normal temperature), and the unit molar mass of the calcium hydroxide is heavier than that of calcium oxide, so that the mass of dried filter residue is heavier than that of dissolved lime; secondly, at low pH, the medium water is less soluble than the industrial water in lime and produces more filter residue.

4. Through the experiment of dropping sodium hydroxide standard solution, the existence of the substance which reacts with alkali to generate precipitate in the reclaimed water can be seen.

Therefore, the lime milk is prepared by using the reclaimed water as a solute, and the effective utilization rate of the lime is reduced.

Example 2

According to the condition that the reclaimed water and the reclaimed water (hereinafter referred to as reclaimed water for short) of the southeast sedimentation tank contain Cl ^- 、SO4 ^2- And suspended matters and the like) and the industrial water have different ion components, the three kinds of water are used for respectively dissolving lime and stone powder with the same mass, the dissolution rates of the lime and the stone powder in the three kinds of water are observed, and the effective utilization rates of the lime and the stone powder are judged according to the dissolution rates.

1. Taking 300ml of reclaimed water, recycled water and industrial water respectively, and weighing;

2. respectively adding 50g of lime into the reclaimed water, the reuse water and the industrial water (the lime is sieved by a 140-mesh sieve to avoid the influence of different impurity contents on experimental data and larger error), and stirring for 30 minutes;

3. filtering the solution (vacuum filtration by a vacuum pump), weighing the filtered filtrate, and obtaining the experimental data shown in table 2;

4. the above experimental procedure was repeated using stone powder instead of lime, and the experimental data are shown in table 3;

TABLE 2

TABLE 3

The specific gravity of the filtered water in the total weight can be shown as follows: the higher the specific gravity of the filtered water, the less precipitate is produced, and vice versa; the higher the specific gravity of the filtered water, the higher the effective utilization rate of lime and stone powder.

As can be seen from the data in table 2: the dissolution reaction conditions of lime with the same mass in different water with the same volume are different; the lime has the most dissolution reaction in industrial water, and the filtered water has the specific weight which is about 2.5 percent higher than that of the used reclaimed water; the lime has a moderate dissolving reaction amount in the reuse water, and the specific gravity of the filtered water in the reuse water is about 1.5 percent higher than that of the reuse water.

As can be seen from the data in table 3: the dissolution reaction conditions of stone powder with the same mass in different water with the same volume are different; the dissolving reaction amount of the stone powder in the industrial water is the largest, and the proportion of the filtered water in the industrial water is 0.23 percent higher than that of the used water; the dissolving reaction amount of the stone powder in the recycled water is moderate, and the specific gravity of the filtered water in the recycled water is about 0.18 percent higher than that of the recycled water.

The lime milk and the stone powder slurry are prepared by using the reclaimed water as a solute, so that the effective utilization rate of lime and stone powder is reduced, and the yield of red mud is increased in the wastewater treatment process.

Test phase

And starting from 5 months and 1 day in 2022, replacing the reclaimed water with industrial water for preparing the water for the lime milk by water treatment, tracking the consumption of lime, the index of wastewater, the consumption of industrial water, the output of red mud and the output of titanium dioxide, comparing the data with the related data of four months before 2022, and analyzing the feasibility and the economic benefit of preparing the industrial water instead of the lime milk.

TABLE 4

As can be seen from the data in table 4: the acid content in month 5 is close to that in the first 4 months, but the ferrous content is highest (the higher the ferrous content, the more lime is consumed); the total lime consumption and the titanium folding consumption corresponding to the titanium dioxide yield are compared, and the total lime consumption and the titanium folding consumption in the month of 5 are the lowest; except that the yield of titanium dioxide in month 2 is limited, under the condition that the yield in other months in month 5 is the same, the lime consumption is reduced by about 2000 tons.

TABLE 5

As can be seen from the data in table 5: performing rapid labor/t at 0.73m higher than that of titanium discharged water discharged in months 1-4, namely performing rapid labor/year at 10800 x 0.73/30=262.8m at multiple discharged water/day; performing nucleic acid division according to 2.7 m/t higher than the yield of titanium discharged water discharged in month 5 and month 4, which is equivalent to performing nucleic acid division according to 10800 x 2.7/30=972m each day; the reason is that the reclaimed water for preparing the lime milk is not recycled, meanwhile, the lime milk prepared from the industrial water finally enters the discharged water, and if the minimum discharged titanium water amount in the table is taken as a standard, 1000m high year of preparing the lime milk by consuming the industrial water every day can be calculated, so that about 3 ten thousand square of the industrial water consumed for preparing the lime milk in month 5 can be calculated.

TABLE 6

From the data in table 4 it can be deduced that: the industrial water is used for replacing reclaimed water to prepare lime milk, so that the consumption of lime is reduced, and the yield of red gypsum is reduced; the data in table 6 is the export transportation amount of red mud in 2022 month, and the export transportation amount of red mud in 5 month is increased because red mud in 4 month cannot be transported in time due to epidemic situation; through calculating that the average red mud produced by the titanium folding machine in 1-3 months is 9.02,1-4 months without process and equipment changes, the amount of red mud produced in 3 months is 100583 tons according to the titanium folding amount of 9.02 red mud, the amount of red mud produced in 4 months is 99220 tons, and the average red mud produced in 4 months is 2700 tons per day, and further the amount of red mud produced in 5 months is 130000-100583+57183.84-99220+69904.89=57285.73t, namely 1 ton of titanium dioxide produces 5.3 tons of red mud; if estimated on site according to red mud: red mud of green houses 1# and 2# is full of green house at the beginning of 5 months, the storage capacity is about 5 ten thousand tons, namely 5 ten thousand tons of red mud are transported more than 5 months, the titanium folding red mud of 5 months can be calculated to be (130000-50000)/10800 =7.4t/t, and the titanium folding red mud of 1-4 months is (110194.33 +79347.8+57183.84+69904.89+ 50000)/(10602 +6874.2+11151.1+ 11000) =9.25t/t; if the reduction of titanium by red mud in 5 months is 1.5 tons/ton calculated according to the minimum difference, it can be estimated that about 15000 tons of red mud can be generated in the preparation of lime milk by using industrial water every month.

The industrial water replaces reclaimed water, so that the lime consumption can be reduced, the lime utilization rate is improved, and the red mud production is reduced. The following is an economic benefit data analysis (month 5 vs. other months):

1. the lime is saved by 2000 tons per month, and the lime unit price is 666 yuan/ton:

2000 x 666=133.2 ten thousand yuan

2. Carrying out single month consumption 30000m high yield and industrial water unit price 5.71 Yuan/m high yield:

30000 × 5.71=17.13 ten thousand yuan

3. If the red mud is produced in 10000 tons per month, the red mud per ton is transported with 65 Yuan/ton:

10000 × 65=65 ten thousand yuan

In summary, monthly savings can be: 133.2-17.13+65=181.07 ten thousand yuan.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (3)

1. The method for treating the titanium white wastewater is characterized by comprising the following steps of:

(1) Mixing lime and industrial water to prepare a mixed solution;

(2) Adding the mixed solution into titanium dioxide wastewater, adjusting the pH value to 8, and neutralizing;

(3) And (4) filtering by using a plate frame, removing impurities, and recycling or discharging the treated water.

2. The method for treating titanium dioxide wastewater according to claim 1, wherein the pH value of the industrial water is 8.6.

3. The method for treating titanium dioxide wastewater according to claim 1, wherein the pH of the titanium dioxide wastewater is 2-3.