Crushing Reduction Ratio
Calculate the reduction ratio of a crusher or mill, RR = F ÷ P, dividing the feed size F by the product size P (usually F₈₀/P₈₀ or crusher openings). The dimensionless result shows how many times the material was reduced in size in one stage. Each equipment type has a typical reduction ratio range: jaw crushers 4-7, cone crushers 5-8, ball mills up to 100 or more. Since each stage has a limited ratio, reducing large blocks to fine powder requires several stages in series, whose product of ratios gives the total reduction. Enter the feed and product sizes.
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Razão de redução de britagem
A razão de redução é a medida mais básica do quanto um britador ou moinho diminui o tamanho do material: RR = F ÷ P, o tamanho da alimentação dividido pelo tamanho do produto. Uma razão de redução de 10 significa que o material saiu dez vezes menor do que entrou. O conceito é central no projeto de circuitos de cominuição porque cada tipo de equipamento tem uma razão de redução limitada, por restrições mecânicas e de eficiência: britadores de mandíbula (primários) atingem 4-7; britadores cônicos (secundários/terciários), 5-8; britadores de impacto, mais (10-20); moinhos de bolas, muito mais (até 100 ou mais, pois moem partículas finas). A consequência prática é que reduzir grandes blocos de rocha de bancada (que chegam a 1 metro) até o pó fino necessário para o beneficiamento (frações de milímetro) exige vários estágios em série — britagem primária, secundária, terciária, e depois moagem —, porque nenhum equipamento faz tudo de uma vez. A razão de redução total do circuito é o produto das razões de cada estágio. Dimensionar a razão de redução de cada estágio (e, portanto, quantos estágios são necessários) é uma decisão central de projeto, que afeta o número de equipamentos, o consumo de energia e o custo. Informe os tamanhos de alimentação e produto.
Related Tools
Total Reduction Ratio
Calculate the total reduction ratio of a three-stage comminution circuit, RR_total = RR₁ × RR₂ × RR₃, multiplying the reduction ratios of each crusher/mill in series. The dimensionless result is the circuit's overall size reduction — from bench rock blocks (hundreds of mm) to fine particles (mm or µm). Since each stage has a limited reduction ratio (4 to 10 for crushers), large total reductions (100, 1000 or more) require several stages in series: primary, secondary, tertiary crushing and milling. Enter the reduction ratios of the three stages.
Powder Factor
Compute the powder factor of a rock blast by dividing the explosive mass (kg) by the volume of rock broken (m³), in kg/m³. It is the central parameter of the blast design: too low produces boulders and poor fragmentation; too high wastes explosive and increases vibration and flyrock. Optimizing it reduces downstream crushing costs. Enter the explosive mass and the rock volume.
Compression Ratio (Refrigeration)
Compute a refrigeration system's compression ratio, rc = Pcondensation/Pevaporation, the ratio of the compressor's absolute discharge to suction pressures. High ratios (above ~10) lower volumetric efficiency, raise the discharge temperature (risking oil and refrigerant degradation) and may require two-stage compression — common at low temperatures and in cryogenics. Enter the condensation and evaporation pressures (absolute).
Concentration Ratio
Compute the concentration ratio of a processing operation, CR = feed mass / concentrate mass, how many tonnes of raw ore are needed to produce one tonne of concentrate. It measures the degree of upgrade: high ratios indicate lean ores that require heavy processing. It is useful in the mass balance and plant sizing. Enter the feed mass and the concentrate mass.
Stripping Ratio (SR)
Compute the stripping ratio (SR) of an open-pit mine by dividing the amount of waste (worthless rock that must be removed) by the ore extracted. It is the central economic indicator of open-pit mining: the higher the SR, the more useless material is moved per tonne of ore, and the higher the cost. It defines the pit limit and the viability of the operation. Enter the waste and ore quantities.
Grinding Energy (Bond Work Index)
Calculate the specific comminution (grinding/crushing) energy by Bond's law, W = 10 × Wi × (1/√P₈₀ − 1/√F₈₀), from the ore's Bond work index Wi (kWh/t), and the particle sizes passing 80% of the product (P₈₀) and feed (F₈₀), in micrometers. The result, in kWh per tonne, is the energy needed to reduce the ore from feed to product size. Comminution is mining's largest energy consumer (up to 50% of the plant). The Wi index characterizes the ore's resistance to fragmentation. It is the basis for sizing mills and energy consumption. Enter the Wi, P₈₀ and F₈₀.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.