Mining - Dynamis

Dynamis has many solutions to reduce your production cost. Take a look at some situations in which our actuation has delivered excellent results:

1 - My cost with fuel in kiln is too high

In order to reduce cost with fuel in kiln, we present two main solutions developed with Dynamis technology:

Fuel substitution from liquid to solid/gaseous

Solid fuels, such as petcoke and coal, or gaseous, such as natural gas and LPG, may present as lower cost alternatives compared to liquid fuels. Forsuch substitution, adjustments to the system’s operational conditions are required, such as installing mills to reduce fuel particle size in the case of solids or an adjustment in the burner geometry in case of gaseous fuels.

To assist the customer in the decision-making, Dynamis studies the technical feasibility of such substitution, also verifying if the expected return on investment is according to the client’s needs. If the customer approves the substitution, Dynamis can then elaborate the whole project related to fuel replacement and supply the necessary equipment, always aiming on cost reduction and productivity increase for the client.

Energy efficiency study

Through a detailed energy efficiency study, it is possible to reduce fuel consumption in the kiln. This study aims to identify operational conditions that undermine the system’s efficiency. Features such as false air intake, incomplete combustion, and exhaust gases at high temperatures are potential improvements. Dynamis team, by means of its extensive experience in the thermal, energy and fluid fields, identifies processes that can be optimized and proposes alternatives for an increase in the kiln’s energy efficiency, to meet the client’s need, respecting the operational limitations of the system.

Use of high sulfur fuel

The use of fuels with high Sulphur content, specially petcoke with high Sulphur content, are an option for cost reduction compared with mineral coal, oils and even compared with the petcoke with low Sulphur content.

High levels of Sulphur in fuel are related to higher recirculation of fines. Usually this amount of powder compromises the kiln stability and consequently the size and shape of clinker crystals.

The optimized burner tip geometry and the operational parameters associated with the primary air, specially flows, pressures and injection velocities in D-Flame burners offset the negative effects of Sulphur in the kiln. This is proven by the installation of the D-Flame in the W8 kiln of Votorantim Cimentos plant in Rio Branco do Sul/PR – Brazil. Even operating with high Sulphur petcoke (5 to 6% Sulphur), the kiln stabilized faster than usual, and produced clinker crystals 14% smaller compared to the kiln results with the previous burner.

2 - My fuel cost with drying is too high

In order to reduce cost with drying, we present two main solutions developed with Dynamis technology:

Use of pulverized solid fuels in hot gas generators

The use of pulverized solid fuel as a substitute for oil or gas in hot gas generators can significantly reduce operational costs for grinding and drying. Generally, this fuel replacement entails a high implementation cost due to the need for large-sized equipment and/or significant changes in layout.

The D-Gasifier is a compact gasifier, which can be installed in an already existing hot gas chamber, replacing the conventional oil or gas burner, and it requires minimal layout modifications.

In an ore reduction kiln at a plant located in Goiás, Dynamis replaced the existing combustion chamber by the D-Gasifier, with the goal of reducing oil fuel consumption, maximizing the substitution for petcoke. Since this equipment gasifies the fuel with a very high efficiency, the mine had a cost-saving equivalent to the direct fuel price difference (R$/cal).

Energy efficiency study

Through a detailed energy efficiency study, it is possible to reduce fuel consumption with drying. This study aims to identify the operational conditions that undermine the system’s efficiency. One of the many ways to reduce fuel costs in drying process is by reusing hot gases from other stages of the system. Gases from other processes can be redirected as input into the dryer. With the reuse of this heat, the energy needed to raise the temperature is reduced, consequently reducing fuel consumption. Another example of cost reduction would be the implementation of a mechanical or thermal system for pre-drying the dryer feed, thereby reducing fuel consumption to heat and evaporate the water.

These are just a few of the many cases of energy efficiency assessment that Dynamis can study. The technical team, by means of its extensive experience in the thermal, energy and fluid fields, identifies processes that can be optimized and proposes alternatives for an increase in the dryer’s energy efficiency, to meet the client’s need, respecting the operational limitations of the system.

3 - My cost with electricity is too high

In order to reduce cost with electricity, we present three main solutions developed with Dynamis technology:

WHR

There are several sources of residual heat in cement, lime and pozzolan plants. Among them are exhaust gases, hot air and hot liquids from chillers, and waste gas from kiln. This waste heat can be used for the generation of electricity, through a Waste Heat Recovery system, which reuses this thermal energy to generate steam that drives the turbines, in a process called cogeneration.

Dynamis has already carried out several studies in the field of residual thermal energy recovery from cement kilns for the generation of electricity. To evaluate the technical-economic feasibility of the project, Dynamis comes up with a few cogeneration alternatives. The competitiveness between them is analyzed by comparing budgets and assembly costs at the local level. Finally, the results of this elaborated analysis results in recommendations to be presented to the client. Dynamis can also evaluate other aspects that can affect the project, such as safety, environmental issues and the electrical integration of the cogeneration unit with the daily operation of the plant.

Energy efficiency study

The high cost of electricity may be related to equipment inefficiency for not operating at its highest energy potential, which impairs productivity.

Through a detailed study of energy efficiency, it is possible to reduce the consumption of electricity. This study aims the identification of operational conditions that undermine the system efficiency. Dynamis team, by means of its extensive experience in the thermal, energy and fluid fields, identifies processes that can be optimized and proposes alternatives for an increase in the kiln’s energy efficiency, to meet the client’s need, respecting the operational limitations of the system.

4 - My emissions of polluting gases are too high

To reduce polluting gas emissions, we present three main solutions developed with Dynamis technology:

Reduction of NOx Emissions

One of the major industry problems is Nitrogen Oxides (NOx) emissions, controlled by environmental agencies. These gases form due to the high temperatures of thermal processes, and many companies cannot control their emissions. Therefore, they are forced to inject gases to reduce NOx, significantly affecting their operational costs.

Dynamis offers a customized and complete solution for the reduction of NOx emissions. Consequently, it has an impact on cost reduction resulted from NOx reduction. This solution starts with a data collection at the customer’s plant and a simulation of the current operational condition. After the simulation, an engineering study involving methods and tools for kiln evaluation is carried out. In this study, computational fluid dynamics simulations are used in the application of complex models to simulate chemical kinetics and turbulence in industrial combustion processes. Thus, it is possible to define which equipment and processes will have the most effect in reducing nitrogen oxides emissions. By the end of the study, Dynamis is able to predict with reasonable precision the possible NOx reduction after implementing the modifications recommended.

Pelletizing furnaces are an example of NOx emitters in the mining industry. The operational conditions of these furnaces, such as high temperatures and high air index, are conducive to the formation of these gases. In such cases, Dynamis may propose some modifications to the system, depending on the results of the preliminary studies. The optimization of the burner tip geometry, the installation of a D-Gasifier or fuel substitution are possible measures for the reduction of NOx emission in pelletizing.

CO

High emission rates of this pollutant result from incomplete combustion caused by insufficient mixing of secondary air with fuel. D-Flame optimized burner tip geometry and primary air operational parameters, particularly flows, pressures and injection speeds, significantly improve mixture of secondary air with fuel, resulting in good combustion, with low CO emissions.

Incomplete combustion can occur specially in burners operated with solid waste, when part of the injected residue falls into the kiln without burning. In such cases, Dynamis technology enables a more horizontal injection of solid waste, so that the residue remains in contact with the flame, increasing its combustion. Dynamis has already developed several successful cases of solid waste injection optimization, which enabled a better combustion, and, consequently, lower CO generation. As a direct result, it is even possible to increase the consumption of solid waste, which is often limited by high CO emission rates.

5 - My product quality is poor

To improve the quality of your product, we propose the following solution involving Dynamis technology:

Study of thermal exchange in CFD (Computational Fluid Dynamics)

Dynamis bets on the highest technology, always looking for innovation. To carry out its projects and develop its equipment, the company uses advanced CFD (Computational Fluid Dynamics) software. Through simulations, it is possible to identify the material’s thermal behavior, calciners, dryers, and other thermal exchange equipment.

A related case was the study in the calcination furnace of a mining company in Goiás using CFD. The movement of the ore, pellets and charcoal was studied, with emphasis on particle segregation and its exposure to radiation, convection and heat conduction. Based on the results, the installation of load stirring elements was studied to evaluate a possible increase in the productivity of the furnace, without leading to a greater drag of dust in the stream of calcination gases.

6 - My system used to produce more than it does today

In order for your system to produce as before, we propose the following solution involving Dynamis technology:

Through a complete diagnosis of your system, we identify the bottlenecks, where our team proposes improvements to eliminate them

Whatever causes flow increase without consequently improving productivity can be identified as production bottleneck. In cement, lime and pozzolan industry, the production limiting factor is usually related to the operation of exhaust fan. An example is false air inlet into the kiln or combustion chamber. The unwanted excess of air increases the air flow moved by the exhaust fan, but does not result in an increase in clinker production. The air temperature also has an impact in the exhaust fan efficiency. As it operates for a given volume, the correspondent mass of hot gases is lower. Therefore, a feasible measure to increase the mass of air that is transported by the fan is to cool down the gases by the end of the kiln. In whichever case, Dynamis performs a detailed study on the plant’s operational conditions to identify possible obstacles to higher productivity and, by the end, proposes solutions to increase the system’s efficiency.