Batch Froth Flotation Experiment PDF

Batch Froth Flotation Experiment ================================ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ====================================================================================== **Introduction** Froth flotation is a process used to sep...

Batch Froth Flotation Experiment ================================ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ====================================================================================== **Introduction** Froth flotation is a process used to separate valuable minerals from gangue (waste) minerals. The process relies on the different wettability of the two types of minerals. The valuable minerals are preferentially wetted by air, while the gangue minerals are preferentially wetted by water. This difference in wettability is exploited by adding a frothing agent to the water-mineral slurry. The frothing agent creates small bubbles of air that attach to the valuable minerals. The bubbles of air then rise to the surface of the slurry, carrying the valuable minerals with them. The gangue minerals, which are not attached to the bubbles of air, sink to the bottom of the slurry. **Objectives** 1. Demonstrate how the surface properties are used for the separation of different solids through an adoptive bubble technique 2. Learn the basic principles of froth flotation 3. Observe the separation of valuable minerals from gangue minerals **Materials** - Froth flotation cell - Water - Mineral samples (ore or mineral mixture) - Frothing Reagents (collectors, frothers, pH modifiers, etc.) - Weighing balance - graduated glass pipette - Graduated cylinder - Safety goggles - gloves - Lab coat **Figure 1.1 Froth floatation process** **Procedure** 1. Gather all the required equipment and materials 2. Weigh a specific amount of the mineral sample(s) to be used in the experiment.Grind the mineral sample(s) to a fine powder if necessary. 3. Add the prepared mineral sample(s) into the flotation cell. 4. Fill the flotation cell with a predetermined volume of water. 5. Set up the froth flotation cell. 6. Start the agitation mechanism in the flotation cell to create a turbulent condition 7. Add the desired reagent(s) to the flotation cell according to the recommended dosage. 8. Agitate the cell until foam appears. Observe and monitor the formation of froth on the surface of the flotation cell. 9. Allow the sample to condition in the flotation cell for a specified period while maintaining the agitation. **Safety Precautions** - Frothing Reagents should be handled carefully because they include combustible ingredients. and a skin irritant, hence gloves should be worn when handling it. - Always wear safety goggles and a lab coat when working with chemicals. - Avoid breathing in fumes from chemicals. - Dispose of chemicals properly. **Theory** - Froth flotation is a relatively simple process, but it can be very effective. The process is based on the different wettability of the valuable minerals and the gangue minerals. The valuable minerals are preferentially wetted by air, while the gangue minerals are preferentially wetted by water. This difference in wettability is exploited by adding a frothing agent to the water-mineral slurry. The frothing agent creates small bubbles of air that attach to the valuable minerals. The bubbles of air then rise to the surface of the slurry, carrying the valuable minerals with them. The gangue minerals, which are not attached to the bubbles of air, sink to the bottom of the slurry. - here are several types of reagents used in froth flotation, including: - Collectors: These reagents are used to selectively bind to the surface of the target mineral, making it hydrophobic and allowing it to attach to air bubbles. - Frothers: These reagents are used to create a stable froth layer on top of the slurry by reducing the surface tension of the liquid. - Modifiers: These reagents are used to adjust the pH and other chemical properties of the slurry to optimize the flotation process. - Depressants: These reagents are used to selectively depress the flotation of unwanted minerals, allowing for more efficient separation of the target minerals. - The selection and dosage of these reagents depend on the mineralogical characteristics of the ore, the desired mineral grade, and the flotation equipment used. A thorough understanding of the chemical properties of the minerals and the reagents used is essential for successful froth flotation. **Data Analysis** The type of mineral slurry you use and the kind of frothing agent you use will affect the results of your experiment. However, you ought to be able to see how the valuable minerals are separated from the gangue minerals. Batch Sedimentation =================== \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ====================================================================================== **Introduction** **Objectives** 1. Understand the principles of batch sedimentation and its applications. 2. Gain practical experience in setting up and conducting sedimentation experiments 3. Determine the relationship between time and settling rate at different slurry concentrations and volumes. 4. To be able to design a continuous thickener using experimental batch sedimentation data **Materials** - graduated cylinder with different volume - Water - Stopwatch - Stirring rod - Limestone powder (sedimentary solid ) **Procedure** 5- Stirring was stopped and the height of the interface was noted, for every 2 min time interval. **Safety Precautions** - Always wear safety goggles when working with chemicals. - Avoid breathing in fumes from chemicals. - Dispose of chemicals properly. **THEORY:** - There are several stages in the settling of a flocculates suspension and different zones are formed as the sedimentation proceeds. Usually, the concentration of solids is high enough that the sedimentation of individual particles or flocs is hindered by other solids to such an extent that all the solids at a given level settle at a common velocity.  **FIGURE 2.1** **Batch sedimentation zones** **Application of Batch Settling** - Test to Design a Continuous Thickener: The capacity of a continuous thickener is determined by the fact that the solids initially present in the feed must be able to settle through all zones of slurry concentration from that of the initial feed to that of the underflow. If the area provided is not sufficient, the solids will build up through the settling zone and into the classification zones until finally some solids are discharged in the overflow. It was assumed that the settling rate was a function only of the solid concentration expressed as the volume of solids per unit volume of slurry. This method is based on the mathematical analysis of batch settling presented by Kynch, which showed that the settling rate and the concentration of the zone that limits capacity can be determined by from the single batch settling test - Kynch method is a useful method for designing thickeners where Z is plotted versus as shown in Fig. 2.2. The slope represents the velocity of the particles.C=Z~o~C~o~Z~i~(2.7) - where Zo is the initial height of the sludge, and C~o~ is the initial concentration of the sludge. **FIGURE2.2** **Kynch method** To calculate the area of the thickener we use this equation: A= Q~0~C~0~( - /V)~max~ C~l~ C~u~ NOTATION A= area of thickener Q~0~= volumetric flow rate C~0~ = initial concentration of the solution V= settling velocity C~l~= concentration at the top of settling zone (concentration of layer) C~L~= C~0~Z~0~/Z~i~ C~u~= concentration of underflow (sludge concentration) **Calculation and data analysis** - Plot the batch-settling curve for each run. - Calculate the area of the thickener. - Calculate the settling velocity of the solid particles. - Explain the factors that affect settling velocities, such as particle size, shape, and density, as well as the effect of the sedimentation tank design and operating conditions [Batch Sedimentation DataSheet] =========================================== - **For certain volume and concentrations:-** Time (s) V (ml ) Z~l~(m) Z~i~ (m) V(m/s) C~l~ ( - /V) C~l~ C~u~ ---------- --------- --------- ---------- -------- ------ ------------------------------------------------- Where:- \- Z~i:~ tangent intersects the settling curve \- Z~L:~ the height of the layer (corresponding to interface time ) \- V= the slope **Size reduction by using a Jaw Crusher** \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ====================================================================================== **Introduction** In the field of extractive metallurgy, mineral dressing is the process of separating commercially valuable minerals from their ores. There are two major categories of processing. One is comminution and the other one is separation. The process \"Comminution\" involves size reduction and size-wise classification called screening or separation. The objective of this report is to provide the details of size reduction methods involved in mineral processing using crushing equipment. Crushing is the first step of mineral processing where the ore/rocks from the mine site are fed into the mechanical equipment to reduce the size of masses for subsequent usage by liberating the valuable mineral from the gangue. Size Reduction is mainly done through crushers and mills. Crushing and grinding are the two primary comminution processes. Crushing is normally carried out on the \"run-of-mine\" ore. The grinding process which is normally carried out after crushing, may be conducted on dry or slurred material. **Objectives** 1- To study the comminuting behavior of different materials, using a primary crusher (Jaw Crusher) under various conditions 2- Understand the basic principles of jaw crushing. 3- To calculate the power needed to perform asize reduction for a certain material **Materials**: Feed materialLab jaw crusher, digital electronics weight balance, stopwatch, and sieves with shaker  **FIGURE 3.1** **Jaw crusher** **Theory** **[Empirical law for size reduction]** The laws of size reduction proposed by different people help in determining the energy stone consumed in size reduction, for the creation of a new surface. The most popular size reduction laws are proposed by Kick, Rittinger, and Bond. **[Kick\'s law]** says that the work required for crushing a given quantity of material is constant for a given reduction ratio irrespective of the original size. Mathematically this law can be expressed as download.jpg.......................(3.1) where *k*~k~, kick\'s constant **[Rittinger's law]** Rittinger\_law says that the work required for reduction is directly proportional to the new surface created. Mathematically this law can be expressed as .........................(3.2) where *k*~r~, Rittinger\'s constant **Bond\'s law**says that the work required for crushing and grinding to form particles of size D~p~, from the very large feed is proportional to the square root of the surface-to-volume ratio ofthe product. Mathematically this law can be expressed as [\$\\frac{p}{ṁ}\$]{.math.inline} =0.316 *w*~i~ ([\$\\frac{1}{\\sqrt{}l2} - \\frac{1}{\\sqrt{}l1}\$]{.math.inline}).............(3.3) where K, is Rittinger\'s constant. [Work index] *w*~i~ its defined as the gross energy requirement in kilowatt-hours per ton feed needed to reduce a very large feed to such a size that 80%of percent of the product passes a 100um screen. We can use **Table (3.1) work index for required material** Material Work index ---------------- ------------ limestone 12.74 Phosphate rock 9.92 Cement clinker 13.45 1. Choose a sample of different sizes to be tested and weigh the required amount. 2. measure the average size of the feed. 3. Adjust the jaw gap setting as required. 4. Switch on the jaw crusher. 5. Put the weighted sample in the crusher and immediately start the stopwatch. 6. Once the crushing is complete, stop the stopwatch and record the time. 7. Collect the product. 8. Arrange the test sieves according to the appropriate arrangement and Sieve the product. 9. Weigh the material on each sieve **Safety Precautions** - Always wear safety glasses when operating a jaw crusher. - Never operate a jaw crusher without proper training. - Be aware of the hazards associated with jaw crushing, such as flying debris and noise. - Follow all safety instructions provided by the manufacturer. **[Jaw Crusher Data Sheet]** -Mass of sample \_\_\_\_\_\_\_\_\_\_\_\_\_\_ - Feed rate of crushing \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ -Time to crush material:\_\_\_\_\_\_\_\_\_\_- Particles size of feed \_\_\_\_\_\_\_\_\_\_\_\_\_ \- Particles size of product \_\_\_\_\_\_\_\_\_\_\_\_- Work index \_\_\_\_\_\_\_\_\_\_\_\_ +-----------+-----------+-----------+-----------+-----------+-----------+ | **diamete | **Mass of | **Mass of | **Mass of | **Mass | **Accumul | | r | sieves | empty | particles | fraction* | ative | | of mesh** | &particle | sieves | ** | * | fraction* | | | s | (g)** | | | * | | **(mm)** | (g)** | | **(g)** | | | +===========+===========+===========+===========+===========+===========+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | | | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+