The 2023 mineral resource report for Sierra Madre Gold and Silver's Guitarra silver-gold project near Temascaltepec, Mexico, records a refurbishing program that began in September 2023 to return the plant to operation.
The NI 43-101 La Guitarra Technical Report, a mineral resource estimate for the Guitarra Silver-Gold Project, Temascaltepec, Estado de México, was prepared by TechSer Mining Consultants Ltd. for Sierra Madre Gold and Silver Ltd. and dated 2023. The existing plant uses flotation, and historically it produced a silver-gold concentrate. At the time of the report the plant was not operating, and equipment was being refurbished and repaired in anticipation of resuming operations.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Report | 2023 | Not applicable | TechSer Mining Consultants for Sierra Madre Gold and Silver Ltd. |
| Plant status | Not operating; refurbishment from September 2023 | Not applicable | Not applicable |
| Crushing circuit capacity | 640 | t/d | 10 x 38 inch jaw and 3 ft short-head cone crusher |
| Grinding circuit capacity | 516 | t/d | Three ball mills in parallel |
| Flotation capacity | 620 | t/d | Limited by the conditioner tank |
| Historical grind | 56 to 60% passing 200 Tyler mesh | Not applicable | Not applicable |
| Coarse ore bin | About 100 | t | 10 x 10 inch grizzly |
| Concentrate thickener | 5,000 | ft³ | Two plate-and-frame filter presses |
| Tailings in the TSF | 2.00 to 2.66 | Mt | 180,000 t of remaining space |
| Permitted TSF design | 5.8 | Mt | 30 years of validity from 2019 |
Overview
Ore from the underground mines is stockpiled under a roof in three piles. The plant has crushing, grinding, flotation, concentrate thickening, filtration and drying, and concentrate storage and loading. After evaluating the equipment and infrastructure, the company began a refurbishing and rebuilding program in September 2023 to bring the plant back into operating condition.
Each part of the plant has its own rated capacity: 640 t/d for crushing, 516 t/d for grinding and 620 t/d for flotation, the last set by the conditioner tank. Grinding is therefore the tightest stage.
Key Process Stages
Crushing. A front-end loader feeds a grizzly with 25 cm by 25 cm openings over a coarse ore bin of about 100 t. A 40 hp, 10 by 38 inch jaw crusher works in closed circuit with a double-deck vibrating screen and a 100 hp, 3 ft short-head cone crusher.
Grinding. Crushed ore is conveyed from the fine ore bin to three ball mills in parallel: 5 by 9 ft, 8 by 6 ft and 7 by 10 ft. Each discharges to its own sump and cyclone, with oversize returned to the mill and undersize sent to the flotation conditioning tank.
Flotation. Two parallel circuits are installed. The newer has one 600 ft³ cell, two 300 ft³ cells and two 150 ft³ cells. The older has twelve 100 ft³ cells arranged in banks. The rougher, scavenger and cleaner arrangement has changed many times over the operation's life.
Concentrate handling. Concentrate is thickened in a 5,000 ft³ thickener and filtered in one of two plate-and-frame presses. Under First Majestic, when the presses could not meet an off-take agreement's moisture specification, part of the concentrate was dried in a rotary kiln and blended with filtered concentrate.
Tailings. Flotation tailings are pumped to the tailings storage facility.
Additional Interesting Data and Summary
The tailings facility holds between 2.00 and 2.66 Mt, with 180,000 t of space remaining that would not compromise its stability. A fully permitted design allows for 5.8 Mt of tailings, valid for 30 years from 2019. The analytical and metallurgical laboratory was partly dismantled at the time of the site visit, though the sample preparation dryers, crushers and puck mills were present and working.
In summary, Guitarra is a small, idle silver-gold flotation plant being refurbished for a restart. Its grinding section, at 516 t/d, sets the plant's capacity, and its tailings facility has only limited space left under the current configuration.
Key Processes
- Covered stockpiles and grizzly-fed coarse ore bin
- Jaw and short-head cone crushing in closed circuit with a screen
- Three parallel ball mills with cyclones
- Two parallel flotation circuits
- Concentrate thickening, filter pressing and optional kiln drying
- Tailings storage facility
Source: NI 43-101 La Guitarra Technical Report, La Guitarra Mineral Resource Estimate, Guitarra Silver-Gold Project, Temascaltepec, Estado de México, prepared by TechSer Mining Consultants Ltd. for Sierra Madre Gold and Silver Ltd., 2023.
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
La Guitarra Silver Mine — 2022 Technical Report
La Guitarra Silver Mine — 2022 Technical Report
| Company | Sierra Madre |
| Date | 2022 |
| Region | Temascaltepec, México |
| Commodities | Silver, Gold |
| Mine Type | Underground |
| Throughput | 400 tpd (operating), 500 tpd (capacity) |
| Status | Care and Maintenance |
Executive Summary
This technical report details the recovery methods and processing plant status for the La Guitarra Silver Mine, operated by Sierra Madre. The property is currently under care and maintenance and not producing. The existing processing plant is a flotation facility designed to produce silver and gold ore concentrate.
The plant was last operated at approximately 400 tonnes per day (tpd), with a stated capacity of 500 tpd when all ball mills are functional. The crushing circuit utilizes a primary jaw crusher in closed circuit with a cone crusher. Grinding is performed using four ball mills in parallel, though one has been non-operational since 2016.
Flotation involves multiple cell sizes arranged in rougher, scavenger, and cleaner configurations. Concentrate dewatering utilizes thickener, filter presses, and a rotary kiln for drying. Significant maintenance items, including chute liners and flotation cell reconfiguration, were identified as necessary before plant restart.
Website: https://sierramadregoldandsilver.com/project/la-guitarra-project
Report Date: 2022
Region: Temascaltepec, México
Project Status: Care and Maintenance
Commodity: Silver, Gold
Throughput: 400 tpd (operating), 500 tpd (capacity)
Mine Type: Underground
La Guitarra Silver Mine — NI 43-101 Technical Report
La Guitarra Silver Mine — NI 43-101 Technical Report
| Company | First Majestic |
| Mine | La Guitarra Silver Mine |
| Date | Unknown |
| Region | Temascaltepec, Edo. Mexico, Mexico |
| Commodities | Silver, Gold |
| Mine Type | Underground |
| Throughput | 520 tpd |
| Status | Operating |
Executive Summary
The La Guitarra Silver Mine utilizes a flotation processing method to recover silver and gold-bearing minerals. The plant has an installed capacity of 520 tonnes per day and processes ore through a two-stage crushing circuit followed by ball mill grinding. The ground ore undergoes bulk flotation to produce a concentrate, which is then thickened and filtered before shipment.
The processing flowsheet includes primary jaw crushing and secondary cone crushing to reduce ROM material to minus 3/8 inches. Four independent ball mill circuits grind the ore to a P80 of 115 µm. Flotation consists of primary rougher, scavenger, and cleaner stages using Wemco cells. Final concentrates are thickened and filtered to approximately 10% humidity for transport to the port of Manzanillo.
Tailings are pumped to an impoundment 1.3 km away, with 92% of plant water requirements met through recycled water from the tailings and concentrate thickening processes.
Website: https://www.firstmajestic.com/investors/news-releases/first-majestic-announces-closing-sale-of-la-guitarra-to-sierra-madre
Report Date: Unknown
Region: Temascaltepec, Edo. Mexico, Mexico
Project Status: Operating
Commodity: Silver, Gold
Throughput: 520 tpd
Mine Life:
Mine Type: Underground
Ore type:
Guitarra Silver-Gold Project — 2023 Technical Report
Guitarra Silver-Gold Project — 2023 Technical Report
| Company | First Majestic |
| Date | 2023 |
| Region | Temascaltepec, México |
| Commodities | Silver, Gold |
| Mine Type | Underground |
| Throughput | 516 t/d |
| Status | Development |
Executive Summary
This section of the NI 43-101 Technical Report details the recovery methods for the Guitarra Silver-Gold Project located in Temascaltepec, México. The existing processing plant utilizes flotation recovery to produce a silver-gold concentrate. Although the plant is currently not in operation, equipment is undergoing refurbishment and repair with the goal of resuming operations. The flowsheet includes a crushing circuit, grinding circuit, and flotation plant with associated dewatering and tailings facilities.
The crushing circuit processes underground ore stockpiled under a roof, feeding into a primary jaw crusher in closed circuit with a vibrating screen and a secondary cone crusher. The grinding circuit consists of three ball mills operating in parallel, discharging into cyclones for classification. The flotation plant comprises two parallel circuits with varying cell sizes, constrained by the conditioner tank capacity.
Tailings are managed in a Tailings Storage Facility (TSF) with remaining capacity for approximately 180,000 tonnes, though a fully permitted design exists for 5.8 million tonnes. A refurbishing and rebuilding program commenced in September 2023 to restore the plant to operational condition.
Website: https://www.firstmajestic.com/investors/news-releases/first-majestic-announces-proposed-sale-of-the-la-guitarra-silver-mine
Report Date: 2023
Region: Temascaltepec, México
Project Status: Development
Commodity: Silver, Gold
Throughput: 516 t/d
Mine Life:
Mine Type: Underground
Ore type:
