Jaw crusher capacity calculation for epidiorite 135 tph

For UK quarry operators processing epidiorite – a dense, hard metamorphic rock widely used in road construction and concrete aggregates – accurate jaw crusher capacity calculation is the foundation of a well‑designed crushing circuit. A 135 tph target requires careful consideration of crusher size, settings, and material properties. This guide provides a practical method to calculate the required capacity and select the right jaw crusher for your epidiorite operation. Note: Product data are constantly updated; the latest specifications should be confirmed with our online customer service.

Understanding epidiorite properties for capacity calculation

Before applying any formula, you need to know the key physical characteristics of epidiorite that affect crusher capacity. Epidiorite is a metamorphosed dolerite (diabase) with properties similar to basalt and diorite. It is hard, compact, and typically has a specific gravity of 2.6–3.0 t/m³, with compressive strength often exceeding 175 N/mm².

For a 135 tph target, bulk density is a critical input. Many standard capacity tables assume a density of 100 lb/ft³ (approximately 1.6 t/m³) for dry, friable stone. However, epidiorite is significantly denser – typically 2.8–2.9 t/m³. Using the correct density ensures your crusher selection is not under‑sized. All performance data in this article is for reference only; actual results depend on site‑specific conditions.

The Taggart capacity formula

A widely used empirical formula for estimating jaw crusher capacity is Taggart’s equation:

Q = 60 × W × S × N × d × ρ × (1 – e)

Where:

• Q = Capacity (tph)

• W = Width of the crushing chamber (m)

• S = Stroke length (m) – the throw of the jaw

• N = Rotational speed of the eccentric shaft (RPM)

• d = Closed side setting (CSS) in metres

• ρ = Bulk density of material (t/m³)

• e = Eccentricity factor (~0.2 for typical applications)

This formula calculates the volume of material discharged per cycle, multiplied by the number of cycles per minute, then converted to tonnes per hour. It provides a theoretical maximum capacity that must then be adjusted for real‑world factors such as feed gradation, moisture, and liner wear.

Step‑by‑step capacity calculation for epidiorite

To determine the jaw crusher capacity for epidiorite 135 tph, follow this practical approach:

Step 1 – Determine feed size and CSS

For a 135 tph epidiorite operation, the maximum feed size should not exceed 80% of the crusher gape and width opening. If your run‑of‑quarry feed is up to 500 mm, you would need a crusher with a gape of at least 625 mm. A typical CSS for primary crushing of epidiorite is 100–150 mm (0.10–0.15 m).

Step 2 – Select a candidate crusher and gather its parameters

Consider a jaw crusher with the following specifications (representative of a mid‑sized unit suitable for 135 tph):

Step 3 – Apply the formula

Q = 60 × 0.9 × 0.025 × 300 × 0.12 × 2.8 × (1 – 0.2)
Q = 60 × 0.9 × 0.025 × 300 × 0.12 × 2.8 × 0.8
Q = 60 × 0.9 = 54
54 × 0.025 = 1.35
1.35 × 300 = 405
405 × 0.12 = 48.6
48.6 × 2.8 = 136.08
136.08 × 0.8 = 108.9 tph

The theoretical capacity is approximately 109 tph – below the 135 tph target.

Step 4 – Adjust to meet target

To reach 135 tph, you can:

• Increase CSS slightly (e.g., from 0.12 m to 0.14 m)

• Select a wider crusher (e.g., W = 1.0 m)

• Choose a model with higher RPM (e.g., 320 RPM)

For a 0.9 m crusher at 0.14 m CSS, the capacity becomes:

Q = 60 × 0.9 × 0.025 × 300 × 0.14 × 2.8 × 0.8 = 127 tph

Increasing RPM to 320 at the same 0.14 m CSS:

Q = 60 × 0.9 × 0.025 × 320 × 0.14 × 2.8 × 0.8 = 135.5 tph

All capacity calculations in this article are for illustration only. Actual crusher performance depends on feed gradation, moisture, and operating conditions. Contact our team for a site‑specific recommendation.

Factors that affect real‑world capacity

Even with accurate calculations, several factors can reduce actual throughput below theoretical values:

• Feed gradation – A well‑graded feed (mix of coarse, medium, and fine) increases capacity by 10‑20% compared to a feed with mostly large boulders.

• Liner wear – As jaw plates wear, the effective CSS increases and capacity changes. Plan CSS adjustments every 200‑300 hours.

• Moisture content – Epidiorite is typically dry, but moisture above 5‑8% can cause packing and reduce capacity by 15‑30%.

• Feed rate consistency – A choke‑fed condition ensures the crusher operates at full capacity. Uneven feeding reduces effective capacity by 20‑30%.

Many UK quarry operators have achieved 135 tph consistently by using a well‑sized jaw crusher with a choke‑fed condition and a well‑maintained grizzly feeder. All performance data in this article is for reference only.

Manufacturer capacity tables: a practical reference

While formulas provide estimates, manufacturer capacity tables are based on actual field performance data and are often more reliable for final selection. For a jaw crusher equivalent to a 24″ x 48″ (610 x 1220 mm) or similar size, typical capacities at various CSS settings (for standard density material of 1.6 t/m³) are:

These capacities are based on standard conditions: dry, medium‑hard rock with a density of 1.6 t/m³. For epidiorite with a density of 2.8 t/m³, the capacity increases proportionally – approximately 75% higher than the table values. A 24″ x 48″ crusher at 125 mm CSS would deliver approximately 270 tph for epidiorite, providing ample margin for the 135 tph target. For a Type J-900x1200 jaw crusher with a 132‑160 kW motor, a CSS of 110‑120 mm typically delivers 180‑230 tph, making it a widely used configuration for hard rock applications.

When performing a jaw crusher capacity calculation for epidiorite 135 tph, a Type J-900x1200 at 110‑120 mm CSS is a practical choice. This size provides a safety margin (operating at 70‑80% of maximum capacity) while handling occasional feed surges. All capacity data in this article is for reference only; contact our team for current, site‑specific information.

Why OCP is your trusted partner for jaw crusher sizing in the UK

Understanding jaw crusher capacity calculation for epidiorite 135 tph is only the first step – selecting the right crusher for your UK quarry requires expert guidance. OCP Mechanical Company has four decades of experience in crushing equipment for hard rock applications. Our 24/7 online team helps with capacity simulations, CSS selection, and wear part optimization. We keep common jaw plates and spare parts in our European warehouse for fast delivery to UK ports. We invite you to request a no‑obligation quote and free capacity assessment.

For a no‑obligation jaw crusher capacity calculation for epidiorite 135 tph tailored to your site, simply click the live chat icon on this page. Our online customer service team is available 24 hours a day, 7 days a week, to provide free price quotes, equipment recommendations, and installation support – helping you crush epidiorite efficiently and profitably.