What is a Mineral Processing Flowsheet and Why Do You Need One?

If you work in mining, metallurgy or process engineering, you have almost certainly encountered a flowsheet. But what exactly is a mineral processing flowsheet, what does it show, and why is it such an essential document? This guide answers all of these questions — whether you are a student encountering flowsheets for the first time or an experienced engineer looking for a clear explanation to share with others.

What is a Mineral Processing Flowsheet?

A mineral processing flowsheet — also called a process flow diagram or PFD — is a simplified diagram that shows the sequence of operations used to extract and concentrate valuable minerals from ore. It maps the journey of ore from the moment it enters the plant to the point where a final product is produced.

A flowsheet uses standardised symbols to represent equipment such as crushers, mills, screens, flotation cells and thickeners, connected by lines that show the flow of material between them. Labels on the lines identify the streams — feed, concentrate, tailings, overflow, underflow and so on.

What Does a Mineral Processing Flowsheet Show?

A typical mineral processing flowsheet includes:

• Unit operations — the major processing steps such as crushing, grinding, classification, flotation, gravity separation, leaching and dewatering
• Equipment — each unit operation is represented by a symbol for the specific piece of equipment, such as a jaw crusher, ball mill, hydrocyclone or thickener
• Material streams — lines connecting equipment show how material flows through the circuit, with labels identifying each stream
• Mass balance data — flowsheets often include tonnages, grades and recoveries for key streams
• Feed and product streams — where ore enters the circuit and where products (concentrate, tailings, solution) leave

The Main Sections of a Mineral Processing Flowsheet

Most mineral processing flowsheets follow a similar structure, moving from coarse to fine and from physical to chemical separation:

1. Comminution

The first stage is size reduction — breaking the ore down from run-of-mine lumps to a fine particle size where valuable minerals are liberated from the surrounding rock. This typically involves primary crushing (jaw crusher or gyratory crusher), secondary and tertiary crushing (cone crusher or HPGR), and grinding (ball mill, rod mill or AG/SAG mill).

2. Classification

After grinding, the slurry is classified by particle size using hydrocyclones or screens. Coarse particles are returned to the mill for further grinding (this is called a closed circuit). Fine particles that are correctly sized pass on to the next stage.

3. Separation and Concentration

This is the heart of the flowsheet — where valuable minerals are separated from gangue (waste rock). Common separation methods include flotation (for sulphide minerals), gravity separation (for gold, tin and heavy minerals), magnetic separation (for iron ore) and leaching (for gold and copper).

4. Dewatering

The final stage removes water from the concentrate and tailings. Thickeners increase the density of the slurry, while filters remove most of the remaining moisture to produce a filter cake suitable for transport or further processing.

Why Do You Need a Flowsheet?

A flowsheet is one of the most important documents in any mining or metallurgical project. Here is why:

Communication

A flowsheet communicates the process concept clearly and concisely to everyone involved in a project — engineers, geologists, management, investors and regulators. A well-drawn flowsheet can convey in one page what would take many paragraphs of text to describe.

Design and Engineering

Flowsheets are the foundation of plant design. Every piece of equipment, every pipe and every control system starts with the flowsheet. Getting the flowsheet right at the beginning saves enormous time and cost later in the project.

Mass Balance

A flowsheet with mass balance data shows how much material flows through each part of the circuit, what grade it is and what recovery is achieved. This is essential for equipment sizing, operating cost estimation and financial modelling.

Operations and Training

In an operating plant, flowsheets help operators understand the process and troubleshoot problems. New operators are trained using the flowsheet before they ever set foot on the plant floor.

Reporting and Compliance

Flowsheets are required in feasibility studies, environmental impact assessments and regulatory submissions. A professional flowsheet demonstrates that the process has been properly designed and documented.

How to Create a Mineral Processing Flowsheet

Traditionally, flowsheets were drawn by hand or using general-purpose CAD software. Today, dedicated tools make the process much faster and produce more professional results.

A good flowsheet tool for mineral processing should include:

• A library of industry-specific symbols for crushers, mills, screens, flotation cells, thickeners and other equipment
• Simple drag-and-drop editing so you can focus on the process rather than the software
• Export to standard formats (PNG, SVG, PDF) for use in reports and presentations
• Cloud saving so your work is always accessible

PfdLabs was built specifically for this purpose — a web-based diagram editor with 35 isometric 3D industrial symbols covering comminution, classification, separation, hydromet and transport equipment. You can create a professional flowsheet in minutes, directly in your browser, without any installation.