Diploma Project on Potassium Chloride Thickening

Contents

INTRODUCTION

1. Selection and justification of design and technological solutions

1.1. The essence of reconstruction

1.2. Literary review

1.3. Design justification of reconstruction

2. Process Calculations

2.1. Description of the process scheme of dehumidification

2.2. Material Balance

2.3. Calculation of suspension density

2.4. Calculation of dynamic viscosity coefficient of suspension

2.5. Calculation of the main structural dimensions of the apparatus

3. Strength calculations

3.1. Calculation of thickener housing for strength in operating conditions

3.2. Calculation of edge stresses at the point of connection of cylindrical and conical parts of thickener housing

3.4. Calculation of cantilever shaft of thickener

3.5. Calculation of support posts

4. Instrumentation Section

4.1. Introduction

4.2. Description of process control and monitoring scheme

4.3. Justification for selection of control and control points

4.4. Justification of automation equipment selection

4.5. Description of control loop action

5. Technical and economic calculations

5.1. Calculation of production capacity of the main production department of the BKPRU-3 flotation concentration plant of Uralkali OJSC

5.2. Investment planning

5.3. Calculation of cost of production and sale of flotation potassium chloride

5.4. Price policy of Uralkali OJSC

5.5. Calculation of economic indicators of activity of BKPRU-3 of Uralkali OJSC

5.6. Calculation of investment efficiency

6. Safety of production activities

6.1. Occupational safety in the Russian Federation

6.2. Hazardous and harmful production factors

6.3. Properties of raw materials and finished products

6.4. Classification of industrial building according to explosion and fire safety

6.5. Safety measures during operation of potassium chloride production

6.6 Lighting system

6.7. Ventilation system

6.8. Fire fighting measures

6.9. Assessment of the socio-economic effectiveness of measures to improve working conditions

CONCLUSION

LIST OF SOURCES USED

APPLICATION

1 selection and justification of design and technological solutions

1.1 Essence of reconstruction

The essence of the reconstruction of the equipment and technological scheme of dehumidification in the production of flotation potassium chloride at BKPRY3 lies in methods of eliminating shortcomings that directly have a negative effect on the normal course of the technological process. Below are process bottlenecks and proposals for their elimination.

One of these places is a fairly high content of insoluble residue (clay sludge) in the initial ore, which, in the absence of additional technological operations to dehumidify sylvinite before the main sylvinic flotation, will inevitably lead to high caking of the finished product, as well as to the difficulty of the flotation process.

The pre-sludge operation of the ore slurry is extremely important because the sylvin flotation reagent-collector-amine is sensitive to the presence of clay sludge in the initial slurry flotation. Insoluble sludges adsorb amines on their developed surface and reduce the efficiency of sylvin flotation and dramatically increase reagent consumption.

To eliminate the above factors that are negative for the normal flow of the technological process, it is necessary to carry out the process of preliminary removal of clay-carbonate sludges from the ore suspension. Due to the peculiarities of the bleaching process, it is better to perform the task in two stages:

I stage - mechanical discoloration;

Stage II - slurry flotation.

For optimal flow of stage I of the process of desalination in the thickener, it is necessary to maintain the density of sediment in the unloading equal to 1274.5kg/m3.

The current equipment and technological scheme of dehumidification includes: mechanical dehumidification in HC710 hydrocyclones and C15 thickener, slurry flotation in mechanical flotation machines FKM6.3. A bottleneck in the listed list of devices is the C15 thickener due to physical wear and tear, as well as the obsolete design that does not allow automation of the process.

To overcome the above-mentioned disadvantages, I propose to modernize the hardware and technical scheme of desalination in the production of flotation potassium chloride at BKPRU3 by: a) replacing the C15 thickener with a diameter of 15 m with the OUTO KUMPU thickener, b) automating the desalination process .

2 process calculations

2.1 Description of the process scheme of dehumidification

The process of preliminary removal of clay-carbonate sludge from crushed silvinite pulp is carried out in two stages:

Stage I - mechanical dehumidification in hydrocyclones with a diameter of 710 mm (HC710);

Stage II - slurry flotation.

The purpose of the I stage of desalting is to ensure the greatest recovery of insoluble residue with a minimum outlet to the drains of hydrocyclones. The minimum flow of the hydrocyclone drain provides an optimal rate of upflow of pulp in a thickener designed to separate clay and salt particles.

Pulp from sump pos.11 is pumped by pump pos.12 to hydrocyclones pos13. Draining of hydrocyclones by gravity is supplied to thickener pos.22, and condensed sediment enters sumpf pos.23 and is the initial feed of sludge flotation.

According to the scheme, 2 batteries of hydrocyclones are provided (1st operating, 2nd standby). Each battery consists of 4 hydrocyclones. All hydrocyclones are lined with stone casting.

Separation of pulp in hydrocyclones takes place in fraction 0.2 mm. Capacity of one hydrocyclone 200350 m3/h. At load on the section on the initial ore (220 ± 20) t/h, the optimal values ​ ​ of the mechanical sludge removal unit are achieved when the following parameters are maintained:

· density of initial food-: T = 4:1

· sand nozzle diameter - 80-90 mm;

· drain pipe diameter - 150 mm;

· pulp pressure at the hydrocyclone inlet (0.1 ± 0.04) MPa

(1.0 ± 0.4 kgf/cm2);

· number of operating hydrocyclones - 3 pcs.

Discharge of hydroclones with a density: The t = 19.3:1 drift comes to thickener of poses.22 with a diameter of 15 m. In thickener there is a separation of clay slimes from salt particles.

In order to reduce the removal of salt particles into the thickener drain (due to the high upward flow rates of the pulp), the density of the thickener discharge must be maintained at G: T = 12.0.

The salt part (condensed sediment) is removed from the lower conical part of the thickener into the sump pos.23, from where the pump pos.24 returns to the head of the main slurry flotation through the sump pos. 14.

Separation of pulp in thickener takes place in fraction 0.1 mm. Thickener drain is supplied to sumpf pos.25, from where it is pumped by pump pos.26 to pulverizer pos.27.

Sands of hydroclones of poses.13 density: T = 0.8. together with the thickener unloading, pos.9 are supplied to the main slurry flotation to the pulverizer pos.14 and distributed to two 10-chamber flotation machines FKM63 pos. 15.1 and 15.2.

The II step of discoloration is sludge flotation:

Removal of clay-carbonate sludge from sylvinite pulp at the III stage of deblocking is carried out by method of sludge flotation.

A (0.08 ± 0.01)% solution of polyacrylamide (PAA) is used as a reagent-flocculant (formation of floccules) of sludges. The collecting reagents for sludge flotation are the oil emulsion demulsifier (LCD), used as a (10 ± 1)% solution or its substitute (7 ± 1)% neonol solution.

Silvinite pulp with size - up to 1 mm through pulverizer pos.14 is supplied to the main slurry flotation performed in mechanical flotation machines FKM63 pos.15.1, 15.2. On each section there are 2 ten-chamber machines with a boiling layer, having a horizontal grid dividing the chamber into 2 compartments: lower aeration and dispersal compartment, upper - mineralization and flotation.

Creation of boiling or suspended layer above grid surface is ensured by continuous supply of aerated liquid flows from aeration and dispersion zone. Capacity of one chamber is 6.3 m3. Main sludge flotation supply density 13601375 kg/m3.

The flotation machine is equipped with loading and unloading pockets, a gate for regulating the level of pulp in the chamber, valves for emergency unloading of the machine.

The time of sludge flotation in PCM63 machines is 8.3 minutes. The foam product of the main sludge flotation is sent by gravity to the pulverizer pos.21, from which it is sent to the four-chamber flotation machine FKM63 pos.17 for the peppery operation of sludge.

Time of permafrost flotation of sludge is 10 minutes. Density of food of perechistny flotation: T =8.8.

From 4-chamber flotation machine pos.17 foam product is sent by gravity to sumpf pos.25.

4 section of the reel

4.1 Introduction

The potash processing plant needs more automatic control and process control than other mining and chemical ore processing plants, as flotation is complicated by mineral dissolution and crystallization processes, and clay sludge drastically degrades the operation of the plants. A circumstance that complicates the use of various sensors is the need for their operation in concentrated salt solutions.

In order to ensure the production of the required quantity of products with its high quality, it is necessary to choose the most correct mode of the production process and strictly adhere to it. Instrumentation is used for continuous and accurate monitoring of technological processes.

Based on the latest achievements of fundamental and applied sciences, the theory of automatic regulation and control, automation systems are being created on the basis of newly developed devices and regulators. Such systems make it possible to perform the following functions: control of process parameters, information processing, automatic regulation of parameters, remote and automatic control of machines and units and alarm of their condition, ensuring safe operation of technological equipment, optimization of technological processes.

At the plant of flotation processing BKPRU3 of Uralkali OJSC, an automated Lomikont110 control system was introduced with the output of process parameters to the PC. The introduction of an automated process control system allowed us to move to a qualitatively new, more advanced stage in the organization of object control. Application of PC in automated control system allows to efficiently solve problems of optimal process control using its mathematical models, to realize problems of automated start-up and production shutdown.

4.2 Description of process control and monitoring scheme

The operation of the mechanical slurry demixing step is a rather complex production process due to the presence of direct and backward links between the controlled and controlled process parameters.

The greatest efficiency of the mechanical deblocking process is achieved by optimizing such process parameters as the supply pressure of hydrocyclones pos.13, the density of the thickener discharge pos.22.

The mechanical discoloration step is divided into: discoloration in HC710 hydrocyclones and discoloration in OUTO KUMPU thickener.

The area requiring the greatest control is the discoloration in the OUTO KUMPU thickener.

In the OUTO KUMPU thickener, clay sludge is separated from salt particles, i.e., desalted.

To reduce the removal of salt particles into the thickener drain due to the high rates of upward flow of pulp, it is necessary to maintain the density of condensed sediment in the unloading of the thickener in the specified values.

The salt part is removed from the lower conical part of the thickener to the sump pos.23, from where the pump pos.24 returns to the main slurry flotation through the pulverizer pos.14.

The suspension in the thickener is separated by a fraction of 0.1 mm. Thickener drain is supplied to sumpf pos.25, from where it is pumped by pump pos.26 to pulverizer pos.27, and then by gravity it is supplied to thickener with diameter of 30 m with peripheral drive, which is intended for thickening of sludge.

Sands of hydrocyclones pos. 13 together with condensed precipitate of thickener, pos.22 are supplied to the main slurry flotation and through pulverizer, pos.14 are distributed over two ten-chamber flotation machines pos. 15.1 and 15.2.

4.3 Justification for selection of control and control points

We will analyze the process diagram of the mechanical slimming step from the point of view of process control. Earlier, when describing the process diagram, two main devices were identified in which technological processes that are subject to control and regulation take place.

The main device in which to monitor the process is the thickener pos.22. The control and control point is the density of condensed sediment in the unloading of the thickener. For optimal flow of technological process density of condensed sediment should be equal to 1274.5 kg/m3. The suspension thickens in the apparatus by depositing solid particles under the influence of gravity. The density of condensed sediment in the unloading of the thickener is automatically controlled using a denser, regulator, actuator and regulator.

4.4 Justification for selection of automation tools

Position according to scheme 19a, 19b:

ENDRESS + HAUSER MYpro DLM431 - two-wire conductor level converter. Measurement range from 4 to 20 mA. Accuracy class 0.5.

Conductometric level converter - designed to measure the density of liquid media and generate an electrical signal for remote data transmission.

Conductometric densities ENDRESS + HAUSER MYpro TsLM431 are used at mining enterprises, to which BKPRU3 of Uralkali OJSC belongs.

The advantage of this density meter is compactness, ease of installation, reliability, accuracy, as well as the generation of a signal for remote data transmission in electrical form for further processing by the logical microprocessor controller Lomikont110 and PC .

Position according to scheme 19c:

EPP-0020 - electro-pneumatic converter. The input signal is electric - 420 mA, the output signal is pneumatic - 20-100 kPa.

Electro-pneumatic converter is designed for conversion of electric signal into pneumatic one.

Position according to scheme 19g:

MIP-320 - pneumatic actuator. Control signal pressure is 20100 kPa. Supply air pressure is 0.6 MPa. Rod travel is 320mm.

Actuating pneumatic mechanism performs translational movement of rod. Designed to control the regulator (18).

Position according to scheme 19d:

KSH 13 NZh Du200 - ball valve Du200, flange.

Ball valve designed to control flow of liquid media is a throttling device with varying area of flow section.

Lomicont 110 is a logic microprocessor controller, accuracy class 1.

The lomicont 110 processes process state data from the measuring means and also performs logical process control. In addition, the technical capabilities of the Lomicont 110 controller allow you to indicate, record data, signal the emergency or pre-emergency state of the equipment.

The advantages of the Lomicont 110 logic microprocessor controller over the controllers on the relay elements are: a) high reliability due to the small number of electrical circuits and contacts, as a result of which contact sticks and electromagnetic interference are eliminated; b) the use of additional parameters generated by Lomicont 110 itself in the alarm and interlock algorithm for more accurate diagnosis of the pre-emergency and emergency condition of the equipment.