Method for rapidly collecting chlorella and application of obtained algae iron solid

Abstract

The invention discloses a method for rapidly collecting chlorella and an application of an obtained chlorella-iron solid, and relates to the technical field of chlorella collection and utilization. According to the technical scheme, the easily-obtained magnetite powder with the conventional granularity is used for rapidly collecting the chlorella, the technological process is simple, the raw material cost is low, the collected chlorella is adsorbed on the magnetite powder, the chlorella and the magnetite powder serve as production raw materials of the pellets together, traditional carbon is replaced with the chlorella, the calorific value ranges from 4200 kilocalories to 5000 kilocalories and is close to the calorific value of the carbon, and the production cost is low. And the production cost of the pellets is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of collection and utilization of Chlorella, and in particular to a method for quickly collecting Chlorella and application of the obtained algae iron solid. Background Art

[0002] Chlorella belongs to the genus Chlorella of the Chlorophyta, and is a ubiquitous single-cell green algae. It is a spherical single-cell algae with a diameter of 3 to 8 microns. It is one of the earliest life on Earth and appeared more than 2 billion years ago. Chlorella is an efficient photosynthetic plant that reproduces by photosynthesis and is widely distributed. There are 10 to 30 million mature Chlorella per milliliter, which has strong fusion with water and is extremely difficult to filter. At present, the common filtering method for making dried Chlorella is membrane filtration, which is extremely inefficient and not suitable for industrial production.

[0003] Chlorella not only has the physiological function of absorbing iron ions, but also has a strong ability to adsorb iron. When adsorbing trivalent iron ions, the function of algae cells is similar to that of ion exchange resins. There are many dissociable charged groups in their cell walls, intracellular proteins and carbohydrates. These charged groups can adsorb iron ions or iron-containing compounds and exist on the surface of algae cells to form iron sheaths.

[0004] Pellet production generally uses coke or coal powder as internal fuel, and the amount of internal fuel added is usually 0.5%. Low coal powder addition will reduce fuel consumption, but it will also reduce the strength of the pellets; excessive coal addition will lead to fuel waste, cost increase and pellet quality reduction. Based on the mainstream industrial ratio of 0.5% internal fuel, taking standard coal (1 ton of standard coal costs 1,000 yuan, calorific value 7,000 kcal) as an example, the internal fuel cost per ton of pellets is about 5 yuan. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for quickly collecting Chlorella and the application of the obtained algae iron solid, which can quickly collect Chlorella, and the raw materials are relatively conventional, and the product is directly utilized in another way, thereby realizing the full high-value utilization of the material.

[0006] In one aspect, the present invention provides a method for quickly collecting Chlorella, comprising the following steps: Screening of raw materials: the concentration of Chlorella liquid is 10-30 million / ml, and the pH is controlled at 8-11; the FeO mass percentage in magnetite powder is greater than 20%, and after being pressed by a roller mill, the particle size of -200 mesh is ≥80%; The magnetite powder is placed in a sealed container, and then the chlorella liquid is added into the sealed container and stirred thoroughly; After the stirring is completed, the mixture is allowed to stand until the chlorella and the magnetite powder react completely; Finally, algae and water are separated, and the obtained liquid is used for cultivating Chlorella, obtaining an algae-iron solid adsorbed with Chlorella.

[0007] Further, in the test of the dry product of Chlorella liquid, the contents of + K + and Na are both ≤ 0.01%.

[0008] Further, the mass percentage of FeO in magnetite powder is > 20%.

[0009] Further, the mass ratio of magnetite powder to Chlorella liquid is 1:500 - 1000.

[0010] Further, the temperature in the closed container is maintained at 25°C - 35°C.

[0011] Further, the stirring time of Chlorella liquid and magnetite powder is 5 - 6 min, and the standing time is 2 - 2.5 h.

[0012] Further, it also includes the cultivation of Chlorella: the cultivation temperature of Chlorella liquid is 25°C - 35°C. When cultivating Chlorella with fresh water, sodium bicarbonate needs to be added, and the added amount of sodium bicarbonate ensures that the pH value of the solution is controlled at 8 - 11.

[0013] On the other hand, the present invention also provides the application of the algae-iron solid obtained by the above method. It is used for preparing pellet ore. Chlorella is used as internal carbon, and the algae body accounts for 0.5% of the total weight of the pellet ore. Other components are traditional pellet components and their proportions, thereby reducing the production cost of pellet ore.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This technical solution uses easily obtained magnetite powder with conventional particle size to quickly collect Chlorella. The process flow is simple, the raw material cost is low. After collection, Chlorella is adsorbed on the magnetite powder, and they are used together as raw materials for the production of pellet ore. Using the algae body to replace traditional internal carbon, the calorific value is 4200 - 5000 kcal, which is similar to the calorific value of internal carbon, saving the production cost of pellet ore. Specific Embodiments

[0015] To fully understand the purpose, features and effects of the present invention, the present invention will be described in detail through the following specific embodiments, but the present invention is not limited thereto.

[0016] Chlorella and magnetite will react quickly and promote the flocculation of Chlorella. Therefore, a method for quickly collecting Chlorella provided by the present invention includes the following steps: Prepare raw materials: The mass percentage of FeO (ferrous rate) in magnetite powder is > 20%, preferably > 25%; and this magnetite powder needs to be pressed by a roller mill, and the specific surface area is ≥ 1900 cm 2 / g, the particle size - 200 mesh > 80%. FeO carries a positive charge and forms an electric field in the particle surface space.

[0017] Chlorella cultivation: Chlorella can be cultivated with fresh water or salt water. However, in the dry Chlorella product test, the content of K + and Na + cannot exceed 0.01%; when cultivating Chlorella with fresh water, a certain amount of sodium bicarbonate needs to be added, and the addition amount is based on controlling the pH value of the water body between 8 - 11. The Chlorella cultivation temperature is between 25 - 35 °C; the pH value of the water body for cultivating Chlorella is controlled at pH = 8 - 11.

[0018] The concentration of the cultivated Chlorella liquid is 10 million - 30 million per milliliter. The concentration of the Chlorella liquid is the number of Chlorella individuals contained in the liquid.

[0019] Collecting Chlorella: Pour the cultivated Chlorella liquid into a collection pool filled with magnetite powder, and stir it with a stirrer to fully mix the Chlorella and the magnetite powder. Stir once every 5 - 6 minutes, and the stirring time varies according to the different morphologies of the magnetite particles. Among them, the weight ratio of magnetite powder to Chlorella liquid is 1:500 - 1000, and the preferred stirrer is a pneumatic stirrer.

[0020] Separating Chlorella: After stirring, let it stand until the reaction between Chlorella and magnetite powder is complete; finally, perform algae - water separation and discharge the liquid in the form of overflow. The standard for measuring the reaction between Chlorella and iron powder is based on the reduction of FeO. Generally, it is controlled that the FeO in the iron powder is reduced by 0.5 - 2.5% (solid - liquid separation). The separated liquid still contains a certain concentration of Chlorella, and this liquid is used to continue cultivating Chlorella. The algae - iron solid attached with Chlorella obtained by separation is used to prepare pellet ore. Preferably, the standing time is 2 - 2.5 h.

[0021] Use the obtained algae - iron solid to prepare pellet ore. The algae body accounts for 0.5% of the total weight of the pellet ore, replacing the internal - added carbon in the traditional pellet ore. Other components and dosages are the same as those of the traditional pellet ore. Generally, burning one ton of pellet ore consumes 5 kg of standard coal, and the collected Chlorella can replace 5 kg of standard coal. Conduct a combustion test on the pellet ore prepared in this application and the ordinary pellet ore, and compare their calorific values. It can be known that the calorific value released by the pellet ore containing Chlorella is the same as that of the ordinary pellet ore. The Chlorella replaces the internal - added carbon in the ordinary pellet ore, and the carbon dioxide generated by the combustion of the pellet ore is recycled for the cultivation of Chlorella. Cultivating 1 ton of Chlorella generally consumes 1.8 tons of carbon dioxide and can produce 0.9 tons of oxygen.

[0022] According to experimental calculations, the iron ions absorbed and adsorbed by the algae body only account for 8.7% of the total amount of iron ions (the total amount of Fe 2+ and Fe 3+ ), and the iron complex (mainly Fe2+ ) It accounts for about 27% of the total amount of iron ions. The iron ions (Fe 3+ ) precipitation or the organic matter flocculation of algal decomposition products accounts for 63.5% of the total amount of iron ions, which is the majority.

[0023] The ferrous iron rate change was detected using two groups of magnetite powder under the same conditions. One group was the experimental sample, that is, the algal iron solid obtained by collecting Chlorella using the above method, and the other group was the blank sample which was still magnetite powder. The potentiometric titration method was used to compare and detect the ferrous iron rate of the blank sample and the experimental sample. It can be seen that the two data differed by 0.5% - 2.5%, which proved that the ferrous iron rate (FeO) of magnetite powder generally decreased by 0.5% - 2.5% after absorbing Chlorella, and the algal bodies absorbed by magnetite powder generally did not exceed 1% of the total amount of magnetite.

[0024] Taking 1000 yuan per ton of standard coal as an example, 5 kg of standard coal is added to each ton of pellet ore, and the cost of the added standard coal is 5 yuan / ton. Using the Chlorella collected by the algal iron solid of the present invention to completely replace the added standard coal, and the cost of Chlorella is negligible. Therefore, the production cost of the pellet ore with the added algal iron solid is reduced by 5 yuan / ton.

[0025] Finally, it should be noted that: the above-listed are only the preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and variations fall within the scope of the claims of the present invention and its equivalent technologies, they should all be considered as the protection scope of the present invention.

Claims

1. A method for quickly collecting Chlorella, characterized in that, The steps include: Prepare the raw materials: the concentration of Chlorella liquid is 10-30 million / ml, and the pH is controlled at 8-11; the FeO mass percentage in the magnetite powder is greater than 20%, and after being pressed by a roller mill, the particle size of -200 mesh is ≥80%; Collecting Chlorella: placing the magnetite powder in a sealed container, then adding the Chlorella liquid into the sealed container, and stirring thoroughly, and standing the container until the Chlorella and the magnetite powder completely react and precipitate; Separation product: Finally, the algae and water are separated to obtain liquid for Chlorella cultivation.

2. The method for rapidly collecting Chlorella according to claim 1, characterized in that, In the test of dried Chlorella vulgaris liquid, the contents of K + and Na + are both ≤ 0.01%.

3. The method for rapidly collecting Chlorella according to claim 1, characterized in that The mass percentage of FeO in magnetite powder is greater than 20%.

4. The method for rapidly collecting Chlorella according to claim 1, characterized in that, The mass ratio of magnetite powder to chlorella liquid is 1:500-1000.

5. The method for rapidly collecting Chlorella according to claim 1, characterized in that, The temperature in the sealed container is maintained at 25℃~35℃.

6. The method for rapidly collecting Chlorella according to claim 1, characterized in that, The stirring time of Chlorella liquid and magnetite powder is 5~6 minutes, and the standing time is 2~2.5 hours.

7. The method for rapidly collecting Chlorella according to claim 1, characterized in that, It also includes the cultivation of Chlorella: the cultivation temperature of Chlorella liquid is between 25-35℃, and sodium bicarbonate needs to be added to the freshwater cultivation of Chlorella. The amount of sodium bicarbonate added ensures that the pH value of the solution is controlled at 8~11.

8. Application of an algal iron solid, characterized in that, The algae iron solid obtained by the method for quickly collecting Chlorella according to any one of claims 1 to 7 is used to prepare pellets, thereby reducing the use of internal carbon.