# US 4,397,503 A · Auriferous gravel interceptor

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- Number: US 4,397,503 A
- Document ID: US4397503A
- Status: Granted
- Kind: A
- Application number: 06/272,087
- Filed: 1981-06-10
- Granted: 1983-08-09
- Earliest claimed: 1980-06-17
- Inventors: Harry K. Williams
- Web page: https://patentgrep.com/patent/US4397503A

## CPC

- E02F 7/005: {conveying material from the underwater bottom (by pipelines E02F7/10; suction dredgers E02F3/88)}
- E21C 41/26: Methods of surface mining (machines for obtaining, or the removal of, materials in open-pit mines E21C47/00); Layouts therefor
- E21C 50/00: Obtaining minerals from underwater, not otherwise provided for (suction dredgers or component parts thereof E02F3/88; equipment for conveying or separating excavated material E02F7/00; dippers G01N1/12)
- E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00)
- E21C: MINING OR QUARRYING

## Abstract

A continuous belt traverses a river through channels on the river bed and carries intercepted material to the river banks for separation of precious metals and gemstones therefrom. Method and apparatus claimed.

## Claims

### Claim 1

An apparatus for collecting precious metal and gemstones from a river, comprising:
(a) a base with two upward-facing longitudinal channels, placed on the river bed lateral to the direction of flow;
(b) rollers mounted in each of said channels and on both banks, longitudinally in line with said channels;
(c) a continuous belt, passing over rollers in one of said channels, over and around the rollers on one of said banks, over rollers in the other of said channels, and over and around the rollers on the other of said banks;
(d) collection means under the endmost of said rollers on both banks;
(e) power means to move said belt;
(f) gratings affixed to said base across the top of said channels;
(g) flushing means for said channels below said rollers.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein each of said rollers in each of said channels comprises a pair of rollers laterally spaced and mounted at an inwardly downward angle.

### Claim 3 (depends on 1, 2)

The apparatus of claims 1 or 2, and further comprising guide means between said grating and said belts.

### Claim 4 (depends on 1, 2)

The apparatus of claim 1 or 2, wherein said base comprises a linkage of longitudinal sections of convenient size.

### Claim 5

A method of collecting precious metal and gemstones from a river, comprising the steps of:
(a) screening from said river, material moving along the bed of said river and containing said precious metal and gemstones, by positioning a channel member having a screened upper surface laterally across the bed of said river;
(b) collecting said screened material on a belt means moving longitudinally through said channel member, the belt means transporting the screened material to at least one bank of the river;
(c) removing said screened material from said belt means on said at least one bank of the river; and
(d) separating said precious metal and gemstones from said screened material after removal of said screened material from said belt.

### Claim 6 (depends on 5)

The method of claim 5, wherein the belt means is a continuous belt assembly the opposite end of which terminate on respective opposite banks of the river and wherein the belt of the continuous belt assembly presents one surface for collecting said screened material during passage of the belt through the channel in one direction and presents a second surface for collecting said screened material during passage of the belt through the channel in the opposite direction, the screened material being removed from the belt at both ends of the belt.